# kb

id: snowball-earth-20260505-1
file: data/en.wikipedia.org/wiki/Snowball_Earth-1.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
That a bed contains sedimentary structures that could have been formed only by glacial activity; That the bed lay within the tropics when it was deposited. That glaciers were active at different global locations at the same time, and that no other deposits of the same age are in existence. This last point is very difficult to prove. Before the Ediacaran, the biostratigraphic markers usually used to correlate rocks are absent; therefore there is no way to prove that rocks in different places across the globe were deposited at the same time. The best that can be done is to estimate the age of the rocks using radiometric dating, which are rarely accurate to better than a million years or so. The first two points are often the source of contention on a case-to-case basis. Many glacial features can also be formed by non-glacial means, and estimating the approximate latitudes of landmasses even as recently as 200 Ma can be riddled with difficulties. === Palaeomagnetism === The snowball Earth hypothesis was first posited to explain what were then considered to be glacial deposits near the equator. Since tectonic plates move slowly over time, ascertaining their position at a given point


id: snowball-earth-20260505-2
file: data/en.wikipedia.org/wiki/Snowball_Earth-2.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
=== Open-water deposits === It appears that some deposits formed during the snowball period could only have formed in the presence of an active hydrological cycle. Bands of glacial deposits up to 5,500 meters thick, separated by small (meters) bands of non-glacial sediments, demonstrate that glaciers melted and re-formed repeatedly for tens of millions of years; solid oceans would not permit this scale of deposition. It is considered possible that ice streams such as seen in Antarctica today could have caused these sequences. Further, sedimentary features that could only form in open water (for example: wave-formed ripples, far-traveled ice-rafted debris and indicators of photosynthetic activity) can be found throughout sediments dating from the snowball-Earth periods. While these may represent "oases" of meltwater on a completely frozen Earth, computer modelling suggests that large areas of the ocean must have remained ice-free, arguing that a "hard" snowball is not plausible in terms of energy balance and general circulation models. === Carbon isotope ratios === There are two stable isotopes of carbon in sea water: carbon-12 (12C) and the rare carbon-13 (13C), which makes up about 1.109 percent of carbon atoms. Biochemical processes, of which photosynthesis is one, tend to preferentially incorporate the


id: snowball-earth-20260505-3
file: data/en.wikipedia.org/wiki/Snowball_Earth-3.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
These cap carbonates have unusual chemical composition as well as strange sedimentary structures that are often interpreted as large ripples. The formation of such sedimentary rocks could be caused by a large influx of positively charged ions, as would be produced by rapid weathering during the extreme greenhouse following a snowball Earth event. The δ13C isotopic signature of the cap carbonates is near −5‰, consistent with the value of the mantle—such a low value could be taken to signify an absence of life, since photosynthesis usually acts to raise the value; alternatively the release of methane deposits could have lowered it from a higher value and counterbalance the effects of photosynthesis. The mechanism involved in the formation of cap carbonates is not clear, but the most cited explanation suggests that at the melting of a snowball Earth, water would dissolve the abundant CO2 from the atmosphere to form carbonic acid, which would fall as acid rain. This would weather exposed silicate and carbonate rock (including readily attacked glacial debris), releasing large amounts of calcium, which when washed into the ocean would form distinctively textured layers of carbonate sedimentary rock. Such an abiotic "cap carbonate" sediment can be found on top


id: snowball-earth-20260505-4
file: data/en.wikipedia.org/wiki/Snowball_Earth-4.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
=== Initiation of glaciation === A tropical distribution of the continents is, perhaps counter-intuitively, necessary to allow the initiation of a snowball Earth. Tropical continents are more reflective than open ocean and so absorb less of the Sun's heat: most absorption of solar energy on Earth today occurs in tropical oceans. Further, tropical continents are subject to more rainfall, which leads to increased river discharge and erosion. When exposed to air, silicate rocks undergo weathering reactions which remove carbon dioxide from the atmosphere. These reactions proceed in the general form An example of such a reaction is the weathering of wollastonite: The released calcium cations react with the dissolved bicarbonate in the ocean to form calcium carbonate as a chemically precipitated sedimentary rock. This transfers carbon dioxide, a greenhouse gas, from the air into the geosphere, and, in steady-state on geologic time scales, offsets the carbon dioxide emitted from volcanoes into the atmosphere. As of 2003, a precise continental distribution during the Neoproterozoic was difficult to establish because there were too few suitable sediments for analysis. Some reconstructions point towards polar continents—which have been a feature of all other major glaciations, providing a point upon which ice can nucleate. Changes


id: snowball-earth-20260505-5
file: data/en.wikipedia.org/wiki/Snowball_Earth-5.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
=== Breaking out of global glaciation === The carbon dioxide levels necessary to thaw Earth have been estimated as being 350 times what they are today, about 13% of the atmosphere. Since Earth was almost completely covered with ice, carbon dioxide could not be withdrawn from the atmosphere by release of alkaline metal ions weathering out of siliceous rocks. Over 4 to 30 million years, enough CO2 and methane, mainly emitted by volcanoes but also produced by microbes converting organic carbon trapped under the ice into the gas, would accumulate to finally cause enough greenhouse effect to make surface ice melt in the tropics until a band of permanently ice-free land and water developed; this would be darker than the ice and thus absorb more energy from the Sun—initiating a "positive feedback". The first areas to become free of permanent ice cover may have been in the mid-latitudes rather than in the tropics, because a rapid hydrological cycle would have inhibited the melting of ice at low latitudes. As these mid-latitude regions became ice free, dust from them blew over onto ice sheets elsewhere, decreasing their albedo and accelerating the process of deglaciation. Destabilization of substantial deposits of methane hydrates


id: snowball-earth-20260505-6
file: data/en.wikipedia.org/wiki/Snowball_Earth-6.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
== Scientific dispute == The argument against the hypothesis is evidence of fluctuation in ice cover and melting during "snowball Earth" deposits. Evidence for such melting comes from evidence of glacial dropstones, geochemical evidence of climate cyclicity, and interbedded glacial and shallow marine sediments. A longer record from Oman, constrained to 13°N, covers the period from 712 to 545 million years ago—a time span containing the Sturtian and Marinoan glaciations—and shows both glacial and ice-free deposition. The snowball Earth hypothesis does not explain the alternation of glacial and interglacial events, nor the oscillation of glacial sheet margins. There have been difficulties in recreating a snowball Earth with global climate models. Simple GCMs with mixed-layer oceans can be made to freeze to the equator; a more sophisticated model with a full dynamic ocean (though only a primitive sea ice model) failed to form sea ice to the equator. In addition, the levels of CO2 necessary to melt a global ice cover have been calculated to be 130,000 ppm, which is considered by some to be unreasonably large. Strontium isotopic data have been found to be at odds with proposed snowball Earth models of silicate weathering shutdown during glaciation and rapid rates


id: snowball-earth-20260505-7
file: data/en.wikipedia.org/wiki/Snowball_Earth-7.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
In reservoirs of anaerobic and low-oxygen life powered by chemicals in deep oceanic hydrothermal vents surviving in Earth's deep oceans and crust; but photosynthesis would not have been possible there. Under the ice layer, in chemolithotrophic (mineral-metabolizing) ecosystems theoretically resembling those in existence in modern glacier beds, high-alpine and Arctic talus permafrost, and basal glacial ice. This is especially plausible in areas of volcanism or geothermal activity. In pockets of liquid water within and under the ice caps, similar to Lake Vostok in Antarctica. In theory, this system may resemble microbial communities living in the perennially frozen lakes of the Antarctic dry valleys. Photosynthesis can occur under ice up to 20 m thick, and at the temperatures predicted by models, equatorial sublimation would prevent equatorial ice thickness from exceeding 10 m. As eggs and dormant cells and spores deep-frozen into ice during the most severe phases of the frozen period. In small regions of open sea water: polynya. These natural ice holes can occur from the action of winds, currents or a local heat source (e.g. geothermal), even if the surrounding sea is completely frozen over. They could preserve enclaves of photosynthesizers with access to light and CO2 to generate


id: snowball-earth-20260505-8
file: data/en.wikipedia.org/wiki/Snowball_Earth-8.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
The Neoproterozoic was a time of remarkable diversification of multicellular organisms, including animals. Organism size and complexity increased considerably after the end of the snowball glaciations. This rapid development of multicellular organisms may have been the result of increased evolutionary pressures resulting from multiple icehouse-hothouse cycles; in this sense, snowball Earth episodes may have "pumped" evolution, much as glaciations during the Pleistocene are known to have acted as a diversity pump in Antarctica. Alternatively, fluctuating copper levels and rising oxygen may have played a part. Many Sturtian diamictites unconformably overlie copper-mineralised strata in Greenland, North America, Australia, and Africa; the glacial breakup and erosion of rocks heavily enriched in copper during the Sturtian glaciation, combined with the chemical weathering of the Franklin Large Igneous Province, greatly elevated copper concentrations in the ocean. Because copper is an essential component of many proteins involved in mitigating oxygen toxicity, synthesising adenosine triphosphate, and producing elastin and collagen, among other biological functions, this spike in copper concentrations was essential to the explosive evolution of multicellular life throughout the latter portion of the Neoproterozoic. Elevated copper concentrations persisted into the Cambrian explosion at the beginning of the Phanerozoic and likely influenced its course too. One


id: snowball-earth-20260505-9
file: data/en.wikipedia.org/wiki/Snowball_Earth-9.md
category: reference
title: Snowball Earth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Snowball_Earth
date_saved: 2026-05-05T10:00:31.903477+00:00
instance: kb-cron
parent: snowball-earth-20260505-0
summary:
The Snowball Earth 1999 overview by Paul F. Hoffman and Daniel P. Schrag, 8 August 1999 Snowball Earth web site Exhaustive on-line resource for snowball Earth by pro-snowball scientists Hoffman and Schrag. New Evidence Puts 'Snowball Earth' Theory Out In The Cold sciencedaily.com. 2007. Analyses in Oman produce evidence of hot-cold cycles in the Cryogenian period, roughly 850–544 million years ago. The UK-Swiss team claims that this evidence undermines hypotheses of an ice age so severe that Earth's oceans completely froze over. Channel 4 (UK) documentary, Catastrophe: Snowball Earth Archived 29 May 2016 at the Wayback Machine episode 2 of 5, first screened Dec 2008, documentary narrated by Tony Robinson, advocates snowball Earth and contains interviews with proponents. First breath: Earth's billion-year struggle for oxygen New Scientist, #2746, 5 February 2010 by Nick Lane. Posits an earlier much longer snowball period, c. 2.4 – c. 2.0 Gya, triggered by the Great Oxygenation Event. 'Snowball Earth' theory melted BBC News online (2002-03-06) report on findings by geoscientists at the University of St Andrews, Scotland that casts doubt on the snowball Earth hypothesis due to evidence of sedimentary material, which could only have been derived from floating ice on open oceanic waters.


id: somatic-marker-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Somatic_marker_hypothesis-0.md
category: reference
title: Somatic marker hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Somatic_marker_hypothesis
date_saved: 2026-05-05T10:00:33.152759+00:00
instance: kb-cron
parent: somatic-marker-hypothesis-20260505-0
summary:
The somatic marker hypothesis, formulated by Antonio Damasio and associated researchers, proposes that emotional processes guide (or bias) behavior, particularly decision-making. "Somatic markers" are feelings in the body that are associated with emotions, such as the association of rapid heartbeat with anxiety or of nausea with disgust. According to the hypothesis, somatic markers strongly influence subsequent decision-making. Within the brain, somatic markers are thought to be processed in the ventromedial prefrontal cortex (vmPFC) and the amygdala. The hypothesis has been tested in experiments using the Iowa gambling task. == Background == In economic theory, human decision-making is often modeled as being devoid of emotions, involving only logical reasoning based on cost-benefit calculations. In contrast, the somatic marker hypothesis proposes that emotions play a critical role in the ability to make fast, rational decisions in complex and uncertain situations. Patients with frontal lobe damage, such as Phineas Gage, provided the first evidence that the frontal lobes were associated with decision-making. Frontal lobe damage, particularly to the vmPFC, results in impaired abilities to organize and plan behavior and learn from previous mistakes, without affecting intellect in terms of working memory, attention, and language comprehension and expression. vmPFC patients also have difficulty expressing


id: somatic-marker-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Somatic_marker_hypothesis-1.md
category: reference
title: Somatic marker hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Somatic_marker_hypothesis
date_saved: 2026-05-05T10:00:33.152759+00:00
instance: kb-cron
parent: somatic-marker-hypothesis-20260505-0
summary:
In an effort to produce a simple neuropsychological tool that would assess deficits in emotional processing, decision-making, and social skills of OMPFC-lesioned individuals, Bechara and collaborators created the Iowa gambling task. The task measures a form of emotion-based learning. Studies using the gambling task have found deficits in various neurological (such as amygdala and OMPFC lesions) and psychiatric populations (such as schizophrenia, mania, and drug abusers). The Iowa gambling task is a computerized test in which participants are presented with four decks of cards from which they repeatedly choose. Each deck contains various amounts of rewards of either $50 or $100, and occasional losses that are greater in the decks with higher rewards. The participants do not know where the penalty cards are located, and are told to pick cards that will maximize their winnings. The most profitable strategy turns out to be to choose cards only from the small reward/small penalty decks, because although the reward is smaller, the penalty is proportionally much smaller than in the high reward/high penalty decks. Over the course of a session, most healthy participants come to adopt the profitable low-penalty deck strategy. Participants with brain damage, however, are unable to determine the better


id: somatic-marker-hypothesis-20260505-2
file: data/en.wikipedia.org/wiki/Somatic_marker_hypothesis-2.md
category: reference
title: Somatic marker hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Somatic_marker_hypothesis
date_saved: 2026-05-05T10:00:33.152759+00:00
instance: kb-cron
parent: somatic-marker-hypothesis-20260505-0
summary:
Some researchers believe that the use of somatic markers (i.e., afferent feedback) would be a very inefficient method of influencing behavior. Damasio's notion of the as-if experience dependent feedback route, whereby bodily responses are re-represented utilizing the somatosensory cortex (postcentral gyrus), also proposes an inefficient method of affecting explicit behavior. Edmund Rolls (1999) stated that; "it would be very inefficient and noisy to place in the execution route a peripheral response, and transducers to attempt to measure that peripheral response, itself a notoriously difficult procedure" (p. 73). Reinforcement association located in the orbitofrontal cortex and amygdala, where the incentive value of stimuli is decoded, is sufficient to elicit emotion-based learning and to affect behavior via, for example, the orbitofrontal-striatal pathway. This process can occur via implicit or explicit processes. The somatic marker hypothesis represents a model of how feedback from the body may contribute to both advantageous and disadvantageous decision-making in situations of complexity and uncertainty. Much of its supporting data comes from data taken from the Iowa gambling task. While the Iowa gambling task has proven to be an ecologically valid measure of decision-making impairment, there exist three assumptions that need to hold true. First, the claim that it


id: space-animal-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Space_animal_hypothesis-0.md
category: reference
title: Space animal hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Space_animal_hypothesis
date_saved: 2026-05-05T10:00:34.416085+00:00
instance: kb-cron
parent: space-animal-hypothesis-20260505-0
summary:
The space animal hypothesis proposes that reports of flying saucers or UFOs might be caused not by technological alien spacecraft or mass hysteria, but rather by animal lifeforms ("space critters") that are indigenous to Earth's atmosphere or interplanetary space. == Proponents == Multiple authors independently suggested the space animal hypothesis. In 1923, paranormal author Charles Fort mused, "It seems no more incredible that up in the seemingly unoccupied sky there should be hosts of living things than that the seeming blank of the ocean should swarm with life." During the 1947 flying disc craze, a fan of Fort's writings named John Philip Bessor became the first modern proponent of the hypothesis when he authored a letter to the Air Force suggesting that discs might be "animals bearing very little likeness to human beings". In 1949, he wrote to the Saturday Evening Post to suggest that the discs might be "more like octopuses, in mentality, than humans". In 1957, a saucer group's newsletter credited Bessor with the "space animal" idea, and in 1978 he was called the "grand-daddy" of the "space critter" hypothesis. In 1948, the Saturday Evening Post quoted Luis Walter Alvarez's opinion that the "gizmos" appeared to be "alive".


id: trivers-willard-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Trivers–Willard_hypothesis-0.md
category: reference
title: Trivers–Willard hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Trivers–Willard_hypothesis
date_saved: 2026-05-05T10:00:35.561406+00:00
instance: kb-cron
parent: trivers-willard-hypothesis-20260505-0
summary:
In evolutionary biology and evolutionary psychology, the Trivers–Willard hypothesis, formally proposed by Robert Trivers and Dan Willard in 1973, suggests that female mammals adjust the sex ratio of offspring in response to maternal condition, so as to maximize their reproductive success (fitness). For example, it may predict greater parental investment in males by parents in "good conditions" and greater investment in females by parents in "poor conditions" (relative to parents in good conditions). The reasoning for this prediction is as follows: Assume that parents have information on the sex of their offspring and can influence their survival differentially. While selection pressures exist to maintain a 1:1 sex ratio, evolution will favor local deviations from this if one sex has a likely greater reproductive payoff than is usual. Trivers and Willard also identified a circumstance in which reproducing individuals might experience deviations from expected offspring reproductive value—namely, varying maternal condition. In polygynous species, males may mate with multiple females, and low-condition males will achieve fewer or no matings. Parents in relatively good condition would then be under selection for mutations causing production and investment in sons (rather than daughters), because of the increased chance of mating experienced by these good-condition sons.


id: two-gospel-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Two-gospel_hypothesis-0.md
category: reference
title: Two-gospel hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Two-gospel_hypothesis
date_saved: 2026-05-05T10:00:36.789683+00:00
instance: kb-cron
parent: two-gospel-hypothesis-20260505-0
summary:
The two-gospel hypothesis or Griesbach hypothesis is that the Gospel of Matthew was written before the Gospel of Luke, and that both were written earlier than the Gospel of Mark. It is a proposed solution to the synoptic problem, which concerns the pattern of similarities and differences between the three Gospels of Matthew, Mark, and Luke. The hypothesis is generally first credited to Johann Jakob Griesbach writing in the 1780s; it was introduced in its current form by William R. Farmer in 1964 and given its current designation of two-gospel hypothesis in 1979. The two-gospel hypothesis contrasts with the two-source hypothesis, the most popular and accepted scholarly hypothesis. Supporters say that it does not require lost sources like the Q source and was supported by the early Church. Proponents of the two-gospel hypothesis generally also support the traditional claims of authorship as accurate to disciples and their direct associates, which implies the gospels were written comparatively soon after Jesus's death, rather than the later dates of authorship supported by other schools of thought. == Overview == Those who support the hypothesis often accept all the church tradition as reliable. Therefore, a common formulation of the hypothesis is the following: Matthew


id: two-gospel-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Two-gospel_hypothesis-1.md
category: reference
title: Two-gospel hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Two-gospel_hypothesis
date_saved: 2026-05-05T10:00:36.789683+00:00
instance: kb-cron
parent: two-gospel-hypothesis-20260505-0
summary:
== Contrasted with the two-source hypothesis == Proponents generally separate arguments made from the text of the gospels themselves ("internal evidence") and evidence from preserved writings of the early church ("external evidence"). For example, early church documents claim that Mark's Gospel was created after Mark made fifty copies of a series of speeches that Peter had given in Rome. The two-gospel hypothesis leans heavily on this external evidence: it embraces the views of the early church, and claims that a strong reason needs to be provided to justify dismissing the traditions of the early Church maintained over the authorship of the gospels. It also claims that the internal evidence supports Mark being a redactor of Matthew and Luke, as Griesbach argued. The two-source hypothesis, in contrast, is based only on the perceived internal evidence for Marcan priority, such as the brevity and primitivity of Mark, and does not accept the tradition of the early church. Approximately 25% of Matthew and 25% of Luke are identical, but are not found in Mark. This has been explained in the two-source hypothesis as coming from the hypothetical Q document. By the two-gospel hypothesis, this material was copied by Luke from Matthew, but not


id: two-gospel-hypothesis-20260505-2
file: data/en.wikipedia.org/wiki/Two-gospel_hypothesis-2.md
category: reference
title: Two-gospel hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Two-gospel_hypothesis
date_saved: 2026-05-05T10:00:36.789683+00:00
instance: kb-cron
parent: two-gospel-hypothesis-20260505-0
summary:
If Luke had access to the final version of Matthew (as opposed to both drawing independently on other sources), why are there so many significant differences between Luke and Matthew on issues such as Jesus' genealogy, circumstances of birth, and events following resurrection? While Luke and Matthew do share a lot of text which is not present in Mark, almost all of it is confined to teachings and parables. Construction of the gospels in accordance with the two-gospel hypothesis would require Luke to rewrite major parts of Matthew's narrative – even though Matthew was presumably an eyewitness who lived in Jerusalem and was surrounded by other eyewitnesses, and Luke was neither. This hypothesis does not actually necessitate Luke relying on Matthew, only Mark relying on Luke and Matthew. Many proponents argue instead that both Luke and Matthew drew from a "proto-Matthew." "The argument from omission": why would Mark and Peter omit such remarkable and miraculous events as virgin birth of Jesus and particularly his appearance to apostles following resurrection? Both Matthew and Luke explicitly attest that Jesus appeared to the eleven disciples, including Peter, after his resurrection, and it seems incredible that Peter would not testify to that fact in


id: variable-speed-of-light-20260505-0
file: data/en.wikipedia.org/wiki/Variable_speed_of_light-0.md
category: reference
title: Variable speed of light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Variable_speed_of_light
date_saved: 2026-05-05T10:00:38.002917+00:00
instance: kb-cron
parent: variable-speed-of-light-20260505-0
summary:
A variable speed of light (VSL) is a feature of a family of hypotheses stating that the speed of light may in some way not be constant, for example, that it varies with frequency, in space, or over time. Accepted classical theories of physics, and in particular general relativity, predict a constant speed of light in any local frame of reference and in some situations these predict apparent variations of the speed of light depending on frame of reference, but this article does not refer to this as a variable speed of light. Various alternative theories of gravitation and cosmology, many of them non-mainstream, incorporate variations in the local speed of light. Attempts to incorporate a variable speed of light into physics were made by Robert Dicke in 1957, and by several researchers starting from the late 1980s. VSL should not be confused with faster than light theories, which depends on a medium's refractive index or its measurement in a remote observer's frame of reference in a gravitational potential. In this context, the "speed of light" refers to the limiting speed c of the theory rather than to the velocity of propagation of photons. == Historical proposals == === Background


id: variable-speed-of-light-20260505-1
file: data/en.wikipedia.org/wiki/Variable_speed_of_light-1.md
category: reference
title: Variable speed of light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Variable_speed_of_light
date_saved: 2026-05-05T10:00:38.002917+00:00
instance: kb-cron
parent: variable-speed-of-light-20260505-0
summary:
One group, studying distant quasars, has claimed to detect a variation of the fine-structure constant at the level in one part in 105. Other authors dispute these results. Other groups studying quasars claim no detectable variation at much higher sensitivities. The natural nuclear reactor of Oklo has been used to check whether the atomic fine-structure constant α might have changed over the past 2 billion years. That is because α influences the rate of various nuclear reactions. For example, 149Sm captures a neutron to become 150Sm, and since the rate of neutron capture depends on the value of α, the ratio of the two samarium isotopes in samples from Oklo can be used to calculate the value of α from 2 billion years ago. Several studies have analysed the relative concentrations of radioactive isotopes left behind at Oklo, and most have concluded that nuclear reactions then were much the same as they are today, which implies α was the same too. Paul Davies and collaborators have suggested that it is in principle possible to disentangle which of the dimensionful constants (the elementary charge, the Planck constant, and the speed of light) of which the fine-structure constant is composed is responsible


id: virus-world-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Virus_world_hypothesis-0.md
category: reference
title: Virus world hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Virus_world_hypothesis
date_saved: 2026-05-05T10:00:39.173467+00:00
instance: kb-cron
parent: virus-world-hypothesis-20260505-0
summary:
The virus world hypothesis (also called the co-evolution hypothesis or the virus-first hypothesis) proposes that self-replicating virus-like genetic elements existed before cellular life and contributed to its emergence. It is one of the main frameworks used to explain the origin of viruses. Modern viruses are obligate parasites that depend on their cellular hosts, thus it may seem more intuitive for viruses to have originated from cells, such as in the "escape hypothesis". Nevertheless, under a hypothesized virus world, viruses are theorized to be direct descendants of the very first replicons to arise. These primordial soup dwelling replicons could have evolved into archaic virus-like structures, which in turn became the precursors of cellular life forms, with the latter possibly emerging as factories and reservoirs for virus production and dissemination. The hypothesis is considered one of the three classical hypotheses of viral origin, although it is now thought these hypotheses may not be mutually exclusive, as different groups of viruses may have evolved through different routes, or a "chimeric scenario". == History == The idea that viruses represent primordial, pre-cellular forms of life has roots in the earliest decades of virology. Félix d'Hérelle, discoverer of bacteriophages, proposed that virus-like agents might be


id: virus-world-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Virus_world_hypothesis-1.md
category: reference
title: Virus world hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Virus_world_hypothesis
date_saved: 2026-05-05T10:00:39.173467+00:00
instance: kb-cron
parent: virus-world-hypothesis-20260505-0
summary:
=== Chimeric scenario === More recent work has treated the classical hypotheses as complementary. Krupovic, Dolja, and Koonin have proposed a chimeric scenario in which viral replication modules descended from primordial pre-cellular replicators, consistent with the virus-first view, while genes encoding major capsid proteins were independently recruited from cellular hosts at multiple points during the diversification of the virosphere, consistent with the escape hypothesis. New viral lineages could then continue to emerge from cellular sources throughout evolutionary history, explaining the polyphyletic character of the modern viruses. == Criticism == The main issue with the virus world is that all known viruses require a host cell for replication, making a pre-cellular virus inconsistent with the standard definition of a virus as an obligate intracellular parasite. Therefore, the hypothesis has been challenged and the existence of an ancient and independent viral world critiqued. Moreira and López-García of Paris-Saclay University have said that they do not think viruses are older than LUCA and claimed that scientific evidence downright the dismisses the idea. The pair has contended that virus hallmark genes could derive from ancient cellular lineages now extinct, and that viruses lack the structural historical continuity required for inclusion on a tree of


id: weak-continuum-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Weak_continuum_hypothesis-0.md
category: reference
title: Weak continuum hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Weak_continuum_hypothesis
date_saved: 2026-05-05T10:00:40.333929+00:00
instance: kb-cron
parent: weak-continuum-hypothesis-20260505-0
summary:
The term weak continuum hypothesis can be used to refer to the hypothesis that 2 ℵ 0 < 2 ℵ 1 {\displaystyle 2^{\aleph _{0}}<2^{\aleph _{1}}} , which is the negation of the second continuum hypothesis. It is equivalent to a weak form of ◊ on ℵ 1 {\displaystyle \aleph _{1}} . F. Burton Jones proved that if it is true, then every separable normal Moore space is metrizable. Weak continuum hypothesis may also refer to the assertion that every uncountable set of real numbers can be placed in bijective correspondence with the set of all reals. This second assertion was Cantor's original form of the Continuum Hypothesis (CH). Given the Axiom of Choice, it is equivalent to the usual form of CH, that 2 ℵ 0 = ℵ 1 {\displaystyle 2^{\aleph _{0}}=\aleph _{1}} . == References ==


id: weathering-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Weathering_hypothesis-0.md
category: reference
title: Weathering hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Weathering_hypothesis
date_saved: 2026-05-05T10:00:41.568680+00:00
instance: kb-cron
parent: weathering-hypothesis-20260505-0
summary:
Arline Geronimus wrote about the weathering hypothesis the early 1990s to account for health disparities of newborn babies and birth mothers due to decades and generations of racism and social, economic, and political oppression. It is well documented that people of color and other marginalized communities have worse health outcomes than white people. This is due to multiple stressors including prejudice, social alienation, institutional bias, political oppression, economic exclusion, and racial discrimination. The weathering hypothesis proposes that the cumulative burden of these stressors as individuals age is "weathering", and the increased weathering experienced by minority groups compared to others can account for differences in health outcomes. In recent years, social scientists investigated the biological plausibility of the weathering hypothesis in studies evaluating the physiological effects of social, environmental and political stressors among marginalized communities. The weathering hypothesis is more widely accepted as a framework for explaining health disparities on the basis of differential exposure to racially based stressors. Researchers have also identified patterns connecting weathering to biological phenomena associated with stress and aging, such as allostatic load, epigenetics, telomere shortening, and accelerated brain aging. == Origins == The weathering hypothesis was initially formulated by Arline Geronimus to explain the dire


id: weathering-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Weathering_hypothesis-1.md
category: reference
title: Weathering hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Weathering_hypothesis
date_saved: 2026-05-05T10:00:41.568680+00:00
instance: kb-cron
parent: weathering-hypothesis-20260505-0
summary:
Maternal mortality is three to four times higher for Black mothers than white mothers in the United States. Infant mortality is also twice as high for infants born to non-Hispanic Black mothers compared to infants born to non-Hispanic white mothers. Additionally, there are racial disparities for negative birth outcomes like low birth weight, which has been found to influence risk of infant mortality and developmental outcomes after birth, and preterm birth. Across all women, older maternal age is associated with higher rates of these negative outcomes during pregnancy, but studies have consistently found that rates rise more rapidly for Black women than white women. The weathering hypothesis proposes that the accumulation of racial stress over Black women's lives contributes to this observed pattern of racial disparities in maternal health and birth outcomes that increase with maternal age. Research has consistently identified an association between preterm birth and low birth weight in Black women and maternal stress caused by experiences of racism, systemic bias, socioeconomic disadvantage, segregated neighborhoods, and high rates of violent crime. There is biological evidence of weathering, including the finding that Black women have shorter telomeres, a biological indicator of age, when compared with white women of the


id: widom-larsen-theory-20260505-0
file: data/en.wikipedia.org/wiki/Widom–Larsen_theory-0.md
category: reference
title: Widom–Larsen theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Widom–Larsen_theory
date_saved: 2026-05-05T10:00:42.763603+00:00
instance: kb-cron
parent: widom-larsen-theory-20260505-0
summary:
The Widom–Larsen theory is a proposed explanation for supposed Low Energy Nuclear Reactions (LENR) developed in 2005 by Allan Widom and Lewis Larsen. In the paper describing the idea, they claim that ultra low momentum neutrons are produced in the cold fusion apparatuses during weak interactions when protons capture "heavy" electrons from metallic hydride surfaces. One source has held that it is "unlikely the electron energy threshold for neutron production can be reached in a metal lattice system without a substantial energy input". The idea was expanded by Yogendra Srivastava together with Widom and Larsen in 2014, who went on to propose that it could be an explanation for neutrons observed in exploding wire experiments, solar corona and flares, and neutron production in thunderstorms. However, unrealistic concentrations of free electrons are needed for the neutron yield to be a significant component of thunderstorm neutrons, discounting the explanation. == References ==


id: wiseman-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Wiseman_hypothesis-0.md
category: reference
title: Wiseman hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wiseman_hypothesis
date_saved: 2026-05-05T10:00:43.966901+00:00
instance: kb-cron
parent: wiseman-hypothesis-20260505-0
summary:
The Wiseman hypothesis, sometimes called the tablet theory, is a theory of the authorship and composition of the Book of Genesis which suggests that Moses compiled Genesis from tablets handed down through Abraham and the other patriarchs. Originally advocated by P. J. Wiseman (1888–1948) in his New discoveries in Babylonia about Genesis (1936). The book was republished by Wiseman's son, Donald Wiseman, as Ancient records and the structure of Genesis: A case for literary unity in 1985. The hypothesis received some support from R. K. Harrison (1969) but otherwise remained without acceptance in scholarly circles. == History == === P. J. Wiseman === Air Commodore P. J. Wiseman, a British officer who visited many active archaeological sites during his career in the Middle East, found that ancient narrative tablets usually ended in colophons which had a very specific format consisting of three parts: 1) "this has been the history/book/genealogy of..."; 2) the name of the person who wrote or owned the tablet; and 3) a date (such as "in the year of the great earthquake" or "the 3rd year of king so-and-so", etc.). Wiseman noted that there are 11 phrases in Genesis which have the same colophon format, which have


id: wiseman-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Wiseman_hypothesis-1.md
category: reference
title: Wiseman hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wiseman_hypothesis
date_saved: 2026-05-05T10:00:43.966901+00:00
instance: kb-cron
parent: wiseman-hypothesis-20260505-0
summary:
== See also == Mosaic authorship Documentary hypothesis Lower criticism Biblical criticism Dating the Bible == Footnotes == == References == Hamilton, Victor (1990). The Book of Genesis (New International Commentary on the Old Testament Series) 1-17. Grand Rapids: W.B. Eerdmans. ISBN 0-8028-2521-4. Harrison, R.K. (1969). Introduction to the Old Testament. Grand Rapids: Eerdmans. ISBN 978-0-8028-3107-1. Hunger, H. (1968). Babylonische und Assyrische Kolophone (Volume 2 of Alter Orient und Altes Testament). Verlag Butzon & Bercker. Leichty, E. (June 7, 1964). "The Colophon". In Biggs, Robert D.; Brinkman, J A (eds.). Studies Presented to A. Leo Oppenheim: 1964. Chicago: University of Chicago Press. pp. 147–54. Walvoord, John; Zuck, R.B; Baker, Walter L.; Blaising, C. A. (1985). Bible Knowledge Commentary: Old Testament. Colorado Springs: Victor. ISBN 0-88207-813-5. Wiseman, P. J (1958). Creation Revealed in Six Days: The evidence of Scripture confirmed by Archaeology. London: Marshall, Morgan and Scott. Wolf, Herbert (2007). An Introduction to the Old Testament Pentateuch. Chicago: Moody Publishers. ISBN 978-0-8024-4156-0. == Further reading == Harrison, R.K. (June 1994). "From Adam To Noah: A Reconsideration Of The Antediluvian Patriarchs' Ages" (PDF). Journal of the Evangelical Theological Society. 37 (2): 161–168. Hamilton, Donald L., Homiletical Handbook, p. 141, Broadman and Holmann


id: wood-pasture-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-0.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
The wood-pasture hypothesis (also known as the Vera hypothesis and the megaherbivore theory) is a scientific hypothesis positing that open and semi-open pastures and wood-pastures formed the predominant type of landscape in post-glacial temperate Europe, rather than the common belief of primeval forests. The hypothesis proposes that such a landscape would be formed and maintained by large wild herbivores. Although others, including landscape ecologist Oliver Rackham, had previously expressed similar ideas, it was the Dutch researcher Frans Vera, who, in his 2000 book Grazing Ecology and Forest History, first developed a comprehensive framework for such ideas and formulated them into a theory. Vera's proposals, although controversial, came at a time when the role grazers played in woodlands was increasingly being reconsidered, and are credited for ushering in a period of increased reassessment and interdisciplinary research in European conservation theory and practice. Although Vera largely focused his research on the European situation, his findings could also be applied to other temperate ecological regions worldwide, especially the broadleaved ones. Vera's ideas have met with both rejection and approval in the scientific community, and continue to lay an important foundation for the rewilding-movement. While his proposals for widespread semi-open savanna as the predominant


id: wood-pasture-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-1.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
=== The reconstruction of vegetation history === Apart from theoretical considerations, this concept has relied and continues to rely heavily on both field observations and, more recently, on findings from pollen analysis, which allow inferences about the vegetation structure of past epochs. For example, vegetation trends can be reconstructed from the ratio of tree pollen to pollen associated with grassland. Pollen analysis is the most widely used means of generating historic vegetation data and the analysis of pollen data has provided a solid database from which a predominance of forest throughout the early stages of the Holocene of temperate Europe, especially the Atlantic, is generally inferred, although the possibility of regional differences remains open. On that basis, the history of vegetation in Europe is generally reconstructed as a history of forest. Pollen analysis, however, has been criticized for its inherent bias towards wind-pollinated plant species and, importantly, wind-pollinated trees, and has been shown to overestimate forest cover. To account for this bias, a corrective model (REVEALS) is used, whose application leads to results that differ substantially from those drawn from the traditional comparison of pollen percentages alone. Alternatively to or in combination with pollen, fossil indicator organisms – such as


id: wood-pasture-hypothesis-20260505-2
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-2.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
==== Background: grazers and browsers ==== The impact herbivores have on the landscape level depends on their way of feeding. Namely, browsers like roe deer, elk and the black rhino focus on woody vegetation, while the diet of grazers like horse, cattle and the white rhino is dominated by grasses and forbs. Intermediate feeders, like the wisent and the red deer, fall in between. Generally, grazers tend to be more social, less selective in their food choices and forage more intensively. Therefore, their impact on vegetation composition tends to be higher, as well as their ability to maintain open spaces. Since the extinction of the aurochs in 1627 and the wild horse around 1900, none of the remaining large wild herbivores in Europe is an obligate grazer. Similarly, domesticated descendants of aurochs and wild horse, cattle and horse, are now largely kept in stables, factory farms and close to settlements, making them effectively extinct in the landscape. What remains are browsers and mixed feeders – roe deer, red deer, elk, wild boar, wisent and beaver, often in low densities. Backbreeding-projects, such as the German Taurus project and the Dutch Tauros programme are addressing this issue by breeding domestic cattle that


id: wood-pasture-hypothesis-20260505-3
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-3.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
Vera relies on several lines of argument based on experiments, ecology, evolutionary ecology, palynology, history and etymology. One of his main arguments is of an ecological nature; the widespread lack of successful regeneration of light-demanding tree species in modern forests. Especially the lack of regeneration of pedunculate oak, sessile oak (together hereafter addressed as "oak") and common hazel in Europe. He contrasts this reality with European pollen deposits from previous ages, where oak and hazel often form a dominant amount of pollen, making a dominance of these species in previous ages conceivable. Especially in regard to hazel, sufficient flowering is only achieved when enough sunlight is available, i.e. the plant grows outside of a closed canopy. He argues that the only explanation for the great abundance of oak and hazel pollen in previous ages is that the primeval landscape was open, and this contrast forms the principal theorem of his hypothesis. It has also been suggested that oak requires disturbances for successful establishment, disturbance large herbivores may provide. However, pollen records from islands that lacked many of the large grazers and browsers that, according to Vera, were essential for the maintenance of landscapes with an open character in temperate Europe


id: wood-pasture-hypothesis-20260505-4
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-4.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
==== Circular reasoning ==== Vera stressed that the prevailing high-forest theory was born out of observations of spontaneous regeneration in the absence of grazing animals. He argued that the presupposition that these animals do not exert a significant influence on natural regeneration, and thus on the vegetation structure as a whole, has been made without comparative confirmation, and is therefore a circular argument. Indeed, modern forestry and forest theory arose largely in the modern era and went hand in hand with the ongoing inclosure of common land throughout Europe. A consequence thereof was in many cases a ban of livestock from the forests, which had previously largely been open woodland pastures, often dominated by oaks. These were multifunctional and used for a range of purposes, from pannage and livestock grazing to the harvest of tree hay, coppice, timber and oak galls for the manufacture of ink, as well as for the production of charcoal, crops and fruit. This former usage of forests is often still revealed by a big age gap between tree generations, particularly if the oldest trees are mainly oaks, and many Central European forest reserves originated as common wood-pastures. ==== Shifted baselines ==== In nature conservation, a


id: wood-pasture-hypothesis-20260505-5
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-5.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
Vera pointed out that words like wold and forest used to have different connotations than they do today. While today, a forest is a dense and reasonably large tract of trees, the medieval Latin forestis, from which it derives, assigned open stands of trees, and was a wild and uncultivated land home also to aurochs and wild horses. According to historical sources, these forestis included hawthorn, blackthorn, wild cherry, wild apple and wild pear, as well as oaks, all of which are light-demanding species that cannot regenerate successfully in closed-canopy forest. From this Vera concluded that original wildwoods still existed in Europe during the Medieval period. Thus, when scholars of the 19th and 20th century assumed that grazing animals had destroyed the original European closed-canopy wildwoods, they were misinterpreting these terms. Instead, these forests, he found, had been destroyed following the industrial revolution and the population growth it caused, which in turn caused overexploitation. He further argued that from this initial misinterpretation gave rise to another misinterpretation: that forest regeneration would naturally take place inside the forest. Thus, scholars of the 19th and 20th century such as Elias Landolt (forester) interpreted medieval grazing regulations to allow tree regeneration in coppiced


id: wood-pasture-hypothesis-20260505-6
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-6.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
==== Associational resistance ==== The term associational resistance describes facilitating relationships between plants that grow close to each other, against both biotic and abiotic stresses like browsing, drought, or salinity. In relation to grazed ecosystems, it can allow for the recruitment of trees and other palatable woody species, via thorny nurse bushes, in these environments. It has been proposed and demonstrated that associational resistance can be a key process in grazed environments, ensuring natural succession.In temperate Europe, succession on pastures commonly starts with so called "islets" ("Geilstellen"), patches of dung which are avoided by the herbivores for an amount of time after deposition, sufficient to allow the establishment of relatively unpalatable species such as rushes, nettles and hummocks of tall grasses like tussock grass. These swards, in turn, provide protection for thorny shrubs such as blackthorn, roses, hawthorn, juniper, bramble, holly and barberry during their early years, when they do not yet have protective thorns and are therefore vulnerable. Once the thorny saplings are fully established, they grow bigger over time and subsequently allow other, less resilient species to establish in their thorn protection, forming mantle and fringe vegetation together with species such as guelder rose, wild privet and dogwood.


id: wood-pasture-hypothesis-20260505-7
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-7.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
Although Vera himself limited his argument to the Holocene and the fauna present into historical times, research better supports his claims in regard to earlier interglacials. Modern humans have likely exerted a strong influence in Europe since their first appearance here during the Weichselian glaciation, which has led some researchers to criticize Vera's choice of the early to mid Holocene as his benchmark for pristine nature. Instead, they argue that pristine nature only existed in Europe before the entering of Homo sapiens. They argue that the best model for what a truly natural landscape during a warm period in Europe would look like is the Eemian interglacial, which was the last warm period before the current Holocene, approximately 130,000 to 115,000 years ago, and the last warm period before Homo sapiens. While archaic humans existed in the form of neanderthals, their influence was probably only localised, due to their low population density. During this warm period, paleoecological data indeed suggest that semi-open landscapes, as postulated by Vera, were widespread and common, most likely maintained by large herbivores. Next to these semi-open landscapes, however, the researchers also found evidence for closed-canopy forest. Overall, the Eemian landscape appears to have been very


id: wood-pasture-hypothesis-20260505-8
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-8.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
The effects of the global extinction of megafauna are likely to have been far-reaching and damaging to ecosystems, and continue to be. The late Quaternary extinction event is unprecedented in the Cenozoic (i.e. since the extinction of the non-avian dinosaurs) in its selectivity for large animals. Accordingly, the modern European megafauna-extirpated ecosystems deviate strongly from the megafauna-rich evolutionary norm. Similar to how herds of herbivores like wildebeest, zebra, impala, buffalo, and elephants drive African savanna vegetation patterns, and not vice versa (i.e. the vegetation dictates the activities of these herbivores), it now seems likely that herbivore herds could have provided similar ecosystem functions in the temperate regions before the Quaternary extinctions. In Europe, where many species such as the straight-tusked elephant, two species of Stephanorhinus and the hippopotamus among many others were lost, this meant that their ecosystem functions – such as plant matter consumption and seed dispersal – were lost as well. Without the disturbance these animals provide, it is argued, forests could develop unhindered and landscapes became more uniform. As this is detrimental to species adapted to the presence of megafauna, some scholars advocate for the reintroduction of these animals where possible, or the introduction of modern proxy


id: wood-pasture-hypothesis-20260505-9
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-9.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
The logical consequence of this was that species associated with grasslands, forest fringes and old, open-grown trees disappeared on large scale, since many ecosystems in Europe, including highly species-rich grasslands in Romania, strictly depend on some management and are negatively impacted if the areas are left fallow and overgrown by forest vegetation. Similarly, the displacement of aspen in boreal forests seems to be accelerated more because of increasing competition in the increasingly closed stands than via browsing. In Europe, grasslands were maintained by large herbivores over the last 1,8 million years, resulting in an exceptional diversity of species in many European grasslands. For example, on a wooded meadow in Estonia, 76 species of plant per 1 square metre (11 sq ft) were counted in 2000, making it one of the world's record sites. Similarly high numbers were counted at other locations in Eastern Europe, making the region one of the hotspots for plant species richness on small scale worldwide. However, grasslands in Europe and elsewhere are increasingly under threat, including from forest encroachment following abandonment, ill-conceived forest restoration schemes, overgrazing and agricultural intensification. Especially the notion that most grasslands derive from human management and as such are essentially degraded former


id: wood-pasture-hypothesis-20260505-10
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-10.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
Grazed woodlands, wood-pastures and pastures in Europe harbour high biodiversity. Rare perennial plant species commonly or exclusively associated with these ecosystems in Europe include hellebores, peonies, asphodels, dittany, black false hellebore and bastard balm. The tree layer is often dominated by a number of oak species and many rare, local and threatened species such as Florentine wild apple, Lebanese wild apple, medlar, sorb tree, pears and wild plums are more often found in European silvopastoral systems than in commercial forest. Rare or declining bird species such as the European roller, hoopoe, several species of shrike, owls (scops owl, little owl) as well as wrynecks and middle spotted woodpeckers are attracted by wood-pastures in particular. In Iberia, the semi-natural oak-woodlands known as dehesa/montado are home to endemic species such as the Spanish imperial eagle and the Iberian lynx. Wood-pastures also provide important habitat for many species of invertebrates. Due to the abundance of large, old trees, wood-pastures are especially important for saproxylic beetles. This includes spectacular and rare species such as capricorn beetle, stag beetles (such as Lucanus cervus), variable chafer and click beetles. In the British Isles alone nearly 1800 species of invertebrates depend on decaying wood, including 700 species


id: wood-pasture-hypothesis-20260505-11
file: data/en.wikipedia.org/wiki/Wood-pasture_hypothesis-11.md
category: reference
title: Wood-pasture hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wood-pasture_hypothesis
date_saved: 2026-05-05T10:00:45.187316+00:00
instance: kb-cron
parent: wood-pasture-hypothesis-20260505-0
summary:
== Further reading == Bunzel-Drüke, Margret; Luick, Rainer (2024): "Master builders of biodiversity". Naturschutz und Landschaftsplanung. Jepson, Paul and Blythe, Cain (2020). Rewilding: The Radical New Science of Ecological Recovery, Icon Books Ltd. ISBN 978-1-78578-627-3 Hodder, K.H.; Bullock, J.M.; Buckland, P.C.; Kirby, K.J. (2005). Large Herbivores in the Wildwood and in modern naturalistic grazing systems (Report). English Nature. Kirby, K.J. (May 2004). "A model of a natural wooded landscape in Britain as influenced by large herbivore activity". Forestry. 77 (5): 405–420. doi:10.1093/forestry/77.5.405. Marris, Emma (2011). Rambunctious garden: saving nature in a post-wild world (1st U.S. ed.). New York: Bloomsbury. ISBN 978-1-60819-032-4. OCLC 639161286. Reif, Albert; Gärtner, Stefanie (December 2007). "Die natürliche Verjüngung der laubabwerfenden Eichen-arten Stieleiche (Quercus robur L.) und Traubeneiche (Quercus petraea Liebl.) – eine Literaturstudie mit besonderer Berücksichtigung der Waldweide" (PDF). Waldoekologie Online (in German). Rotherham, Ian D., ed. (2013). Trees, forested landscapes, and grazing animals: a European perspective on woodlands and grazed treescapes. Abingdon, Oxon: Routledge. ISBN 978-0-415-62611-8. OCLC 829911159. Smith, David; Whitehouse, Nicki; Bunting, M. Jane; Chapman, Henry (March 2010). "Can we characterise 'openness' in the Holocene palaeoenvironmental record? Modern analogue studies of insect faunas and pollen spectra from Dunham Massey deer park and Epping Forest,


id: working-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Working_hypothesis-0.md
category: reference
title: Working hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Working_hypothesis
date_saved: 2026-05-05T10:00:46.409821+00:00
instance: kb-cron
parent: working-hypothesis-20260505-0
summary:
A working hypothesis is a hypothesis that is provisionally accepted as a basis for further ongoing research in the hope that a tenable theory will be produced, even if the hypothesis ultimately fails. Like all hypotheses, a working hypothesis is constructed as a statement of expectations, which can be linked to deductive, exploratory research in empirical investigation and is often used as a conceptual framework in qualitative research. The term "working" indicates that the hypothesis is subject to change. == History == Use of the phrase "working hypothesis" goes back to at least the 1850s. Charles Sanders Peirce came to hold that an explanatory hypothesis is not only justifiable as a tentative conclusion by its plausibility (by which he meant its naturalness and economy of explanation), but also justifiable as a starting point by the broader promise that the hypothesis holds for research. This idea of justifying a hypothesis as potentially fruitful (at the level of research method), not merely as plausible (at the level of logical conclusions), is essential for the idea of a working hypothesis, as later elaborated by Peirce's fellow pragmatist John Dewey. In 1890, and again in 1897, Thomas Chrowder Chamberlin wrote "The method of multiple


id: working-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Working_hypothesis-1.md
category: reference
title: Working hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Working_hypothesis
date_saved: 2026-05-05T10:00:46.409821+00:00
instance: kb-cron
parent: working-hypothesis-20260505-0
summary:
Given its success (the working hypothesis), he (the social scientist) may restate his world from this standpoint and get the basis for further investigation that again always takes the form of a problem. The solution of this problem is found over again in the possibility of fitting his hypothetical proposition into the whole within which it arises. And he must recognize that this statement is only a working hypothesis at the best, i.e., he knows that further investigation will show that the former statement of his world is only provisionally true, and must be false from the standpoint of a larger knowledge, as every partial truth is necessarily false over against the fuller knowledge which he will gain later (p. 370). For Putnam, the working hypothesis represents a practical starting point in the design of an empirical research exploration. A contrasting example of this conception of the working hypothesis is illustrated by the brain-in-a-vat thought experiment. This experiment involves confronting the global skeptic position that we, in fact, are all just brains in vats being stimulated by a mad scientist to believe that our reality is real. Putnam argued that this proposition, however, rests on a "magical theory of reference"


id: yamatai-honshu-theory-20260505-0
file: data/en.wikipedia.org/wiki/Yamatai_Honshu_Theory-0.md
category: reference
title: Yamatai Honshu Theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Yamatai_Honshu_Theory
date_saved: 2026-05-05T10:00:47.586257+00:00
instance: kb-cron
parent: yamatai-honshu-theory-20260505-0
summary:
The Yamatai Honshu Theory is the theory that the Yamatai-koku was located in Honshu, specifically Kinai (now Kinki region), where the capital was located in the Kofun period rather than in Kyushu as the Yamatai Kyushu Theory proposes. According to this theory, the Yamatai-koku was essentially continuous with the Yamato Kingship, with its capital in roughly the same region, and the Yamatai-koku transformed into the Yamato Kingship when the Kofun period began. == Overview == In the Edo period, Arai Hakuseki advocated the theory in which he insisted Yamatai-koku was located in the Yamato Province (大和国, Nara prefecture, Honshu). Later, he advocated the different theory, in which he insisted Yamatai-koku was located in the Yamato county (山門郡, Yamato-gun) in the Chikugo Province (Fukuoka prefecture, Kyushu) in his book Foreign Affairs Chronicle. Since then, from the Edo period to the present, the mainstream of the academic world has been largely divided between the "Yamatai Honshu (Kinai) Theory (邪馬台国畿内説)", which has been insisted and supported by Naito Konan et al. and the "Yamatai Kyushu Theory (邪馬台国九州説)", which has been insisted and supported by Shiratori Kurakichi et al. The Kyushu theory, however, is divided into two distinct theories: one that says the Yamataikoku


id: yamatai-kyushu-theory-20260505-0
file: data/en.wikipedia.org/wiki/Yamatai_Kyushu_Theory-0.md
category: reference
title: Yamatai Kyushu Theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Yamatai_Kyushu_Theory
date_saved: 2026-05-05T10:00:48.743589+00:00
instance: kb-cron
parent: yamatai-kyushu-theory-20260505-0
summary:
The Yamatai Kyushu Theory is the theory that the Yamatai kingdom was located in Kyushu rather than in Honshu as the Yamatai Honshu Theory proposes. The theory proposes that the original capital of Japan was located in Kyushu, and when the Kofun period began, the Yamato Kingship moved the capital east to the Kinai region, first in the Yamato Province (Nara prefecture), then Kyoto in the Yamashiro Province (Kyoto Prefecture). == Overview == In the Edo period, Arai Hakuseki adovocated the "Kinai Yamataikoku theory" which says Yamatai-koku was located in 大和 (Yamato Province, ie. Nara prefecture) in the Kinai, Honshu. Later, Arai advocated a different theory, the "Kyūshū Yamataikoku theory" which says Yamatai-koku was located in "Yamato county (山門-郡, Yamato-gun)" in Chikugo Province (Fukuoka prefecture, Northern Kyushu) in his "Foreign Affairs Record". Since then, the mainstream of academic circles has been divided into two major theories: the "Honshu theory" (by Naitō Torajirō et al.) holds that Yamatai-koku was located in Honshu. the "Kyushu theory" (by Shiratori Kurakichi et al.) holds that Yamatai-koku was located in Kyushu. The Kyūshū theory has itself been divided into two schools. One school insists the "Kyushu Yamatai-koku" moved to the East and became the Imperial


id: zoo-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Zoo_hypothesis-0.md
category: reference
title: Zoo hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Zoo_hypothesis
date_saved: 2026-05-05T10:00:49.963140+00:00
instance: kb-cron
parent: zoo-hypothesis-20260505-0
summary:
The zoo hypothesis speculates on the assumed behavior and existence of technologically advanced extraterrestrial life and the reasons they refrain from contacting Earth. It is one of many theoretical explanations for the Fermi paradox. The hypothesis states that extraterrestrial life intentionally avoids communication with Earth to allow for natural evolution and sociocultural development, and avoiding interplanetary contamination, similar to people observing animals at a zoo. The hypothesis seeks to explain the apparent absence of extraterrestrial life despite its generally accepted plausibility and hence the reasonable expectation of its existence. Extraterrestrial life forms might, for example, choose to allow contact once the human species has passed certain technological, political, and/or ethical standards. Alternatively, they may withhold contact until humans force contact upon them, possibly by sending a spacecraft to an extraterrestrial-inhabited planet. In this regard, reluctance to initiate contact could reflect a sensible desire to minimize risk. An extraterrestrial society with advanced remote-sensing technologies may conclude that direct contact with neighbors confers added risks to itself without an added benefit. A variant on the zoo hypothesis suggested by former MIT Haystack Observatory scientist John Allen Ball is the "laboratory" hypothesis, in which humanity is being subjected to experiments, with Earth serving


id: zoo-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Zoo_hypothesis-1.md
category: reference
title: Zoo hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Zoo_hypothesis
date_saved: 2026-05-05T10:00:49.963140+00:00
instance: kb-cron
parent: zoo-hypothesis-20260505-0
summary:
A modified zoo hypothesis is a possible solution to the Fermi paradox. The time between the emergence of the first civilization within the Milky Way and all subsequent civilizations could be enormous. Monte Carlo simulation shows the first few inter-arrival times between emergent civilizations would be similar in length to geologic epochs on Earth. The zoo hypothesis assumes a civilization may have a ten-million, one-hundred-million, or half-billion-year head start on humanity, i.e., it may have the capability to completely negate our best attempts to detect it. The zoo hypothesis relies in part on applying the concept of hegemonic power to the Fermi paradox. Even if a first hegemonic non-interventionist grand civilization (first civilization) is long gone, their initial legacy could persist in the form of a passed-down tradition, or perhaps in an artificial lifeform (artificial superintelligence) dedicated to a non-interventionist hegemonic goal without the risk of death. Thus, the hegemonic power does not even have to be the first civilization, but simply the first to spread its non-interventionist doctrine and control over a large volume of the galaxy. If just one civilization acquired hegemony in the distant past, it could form an unbroken chain of taboo against rapacious colonization in


id: scientific-modelling-20260505-0
file: data/en.wikipedia.org/wiki/Scientific_modelling-0.md
category: reference
title: Scientific modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Scientific_modelling
date_saved: 2026-05-05T10:00:52.576146+00:00
instance: kb-cron
parent: scientific-modelling-20260505-0
summary:
Scientific modelling is an activity that produces models representing empirical objects, phenomena, and physical processes, to make a particular part or feature of the world easier to understand, define, quantify, visualize, or simulate. It requires selecting and identifying relevant aspects of a situation in the real world and then developing a model to replicate a system with those features. Different types of models may be used for different purposes, such as conceptual models to better understand, operational models to operationalize, mathematical models to quantify, computational models to simulate, and graphical models to visualize the subject. Modelling is an essential and inseparable part of many scientific disciplines, each of which has its own ideas about specific types of modelling. The following was said by John von Neumann. ... the sciences do not try to explain, they hardly even try to interpret, they mainly make models. By a model is meant a mathematical construct which, with the addition of certain verbal interpretations, describes observed phenomena. The justification of such a mathematical construct is solely and precisely that it is expected to work—that is, correctly to describe phenomena from a reasonably wide area. There is also an increasing attention to scientific modelling in


id: scientific-modelling-20260505-1
file: data/en.wikipedia.org/wiki/Scientific_modelling-1.md
category: reference
title: Scientific modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Scientific_modelling
date_saved: 2026-05-05T10:00:52.576146+00:00
instance: kb-cron
parent: scientific-modelling-20260505-0
summary:
=== Systems === A system is a set of interacting or interdependent entities, real or abstract, forming an integrated whole. In general, a system is a construct or collection of different elements that together can produce results not obtainable by the elements alone. The concept of an 'integrated whole' can also be stated in terms of a system embodying a set of relationships which are differentiated from relationships of the set to other elements, and form relationships between an element of the set and elements not a part of the relational regime. There are two types of system models: 1) discrete in which the variables change instantaneously at separate points in time and, 2) continuous where the state variables change continuously with respect to time. === Generating a model === Modelling is the process of generating a model as a conceptual representation of some phenomenon. Typically a model will deal with only some aspects of the phenomenon in question, and two models of the same phenomenon may be essentially different—that is to say, that the differences between them comprise more than just a simple renaming of components. Such differences may be due to differing requirements of the model's end users,


id: scientific-modelling-20260505-2
file: data/en.wikipedia.org/wiki/Scientific_modelling-2.md
category: reference
title: Scientific modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Scientific_modelling
date_saved: 2026-05-05T10:00:52.576146+00:00
instance: kb-cron
parent: scientific-modelling-20260505-0
summary:
Rainer Hegselmann, Ulrich Müller and Klaus Troitzsch (eds.) (1996). Modelling and Simulation in the Social Sciences from the Philosophy of Science Point of View. Theory and Decision Library. Dordrecht: Kluwer. Paul Humphreys (2004). Extending Ourselves: Computational Science, Empiricism, and Scientific Method. Oxford: Oxford University Press. Johannes Lenhard, Günter Küppers and Terry Shinn (Eds.) (2006) "Simulation: Pragmatic Constructions of Reality", Springer Berlin. Tom Ritchey (2012). "Outline for a Morphology of Modelling Methods: Contribution to a General Theory of Modelling". In: Acta Morphologica Generalis, Vol 1. No 1. pp. 1–20. William Silvert (2001). "Modelling as a Discipline". In: Int. J. General Systems. Vol. 30(3), pp. 261. Sergio Sismondo and Snait Gissis (eds.) (1999). Modeling and Simulation. Special Issue of Science in Context 12. Eric Winsberg (2018) "Philosophy and Climate Science" Cambridge: Cambridge University Press Eric Winsberg (2010) "Science in the Age of Computer Simulation" Chicago: University of Chicago Press Eric Winsberg (2003). "Simulated Experiments: Methodology for a Virtual World". In: Philosophy of Science 70: 105–125. Tomáš Helikar, Jim A Rogers (2009). "ChemChains Archived 2021-03-03 at the Wayback Machine: a platform for simulation and analysis of biochemical networks aimed to laboratory scientists". BioMed Central. == External links == Models. Entry in the Internet


id: enterprise-modelling-20260505-0
file: data/en.wikipedia.org/wiki/Enterprise_modelling-0.md
category: reference
title: Enterprise modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Enterprise_modelling
date_saved: 2026-05-05T10:00:53.796573+00:00
instance: kb-cron
parent: enterprise-modelling-20260505-0
summary:
Enterprise modelling is the abstract representation, description and definition of the structure, processes, information and resources of an identifiable business, government body, or other large organization. It deals with the process of understanding an organization and improving its performance through creation and analysis of enterprise models. This includes the modelling of the relevant business domain (usually relatively stable), business processes (usually more volatile), and uses of information technology within the business domain and its processes. == Overview == Enterprise modelling is the process of building models of whole or part of an enterprise with process models, data models, resource models and/or new ontologies etc. It is based on knowledge about the enterprise, previous models and/or reference models as well as domain ontologies using model representation languages. An enterprise in general is a unit of economic organization or activity. These activities are required to develop and deliver products and/or services to a customer. An enterprise includes a number of functions and operations such as purchasing, manufacturing, marketing, finance, engineering, and research and development. The enterprise of interest are those corporate functions and operations necessary to manufacture current and potential future variants of a product. The term "enterprise model" is used in


id: enterprise-modelling-20260505-1
file: data/en.wikipedia.org/wiki/Enterprise_modelling-1.md
category: reference
title: Enterprise modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Enterprise_modelling
date_saved: 2026-05-05T10:00:53.796573+00:00
instance: kb-cron
parent: enterprise-modelling-20260505-0
summary:
=== Enterprise model === An enterprise model is a representation of the structure, activities, processes, information, resources, people, behavior, goals, and constraints of a business, government, or other enterprises. Thomas Naylor (1970) defined a (simulation) model as "an attempt to describe the interrelationships among a corporation's financial, marketing, and production activities in terms of a set of mathematical and logical relationships which are programmed into the computer." These interrelationships should according to Gershefski (1971) represent in detail all aspects of the firm including "the physical operations of the company, the accounting and financial practices followed, and the response to investment in key areas" Programming the modelled relationships into the computer is not always necessary: enterprise models, under different names, have existed for centuries and were described, for example, by Adam Smith, Walter Bagehot, and many others. According to Fox and Gruninger (1998) from "a design perspective, an enterprise model should provide the language used to explicitly define an enterprise... From an operations perspective, the enterprise model must be able to represent what is planned, what might happen, and what has happened. It must supply the information and knowledge necessary to support the operations of the enterprise, whether they be performed


id: enterprise-modelling-20260505-2
file: data/en.wikipedia.org/wiki/Enterprise_modelling-2.md
category: reference
title: Enterprise modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Enterprise_modelling
date_saved: 2026-05-05T10:00:53.796573+00:00
instance: kb-cron
parent: enterprise-modelling-20260505-0
summary:
== Enterprise engineering == Enterprise engineering is the discipline concerning the design and the engineering of enterprises, regarding both their business and organization. In theory and practice two types of enterprise engineering has emerged. A more general connected to engineering and the management of enterprises, and a more specific related to software engineering, enterprise modelling and enterprise architecture. In the field of engineering a more general enterprise engineering emerged, defined as the application of engineering principals to the management of enterprises. It encompasses the application of knowledge, principles, and disciplines related to the analysis, design, implementation and operation of all elements associated with an enterprise. In essence this is an interdisciplinary field which combines systems engineering and strategic management as it seeks to engineer the entire enterprise in terms of the products, processes and business operations. The view is one of continuous improvement and continued adaptation as firms, processes and markets develop along their life cycles. This total systems approach encompasses the traditional areas of research and development, product design, operations and manufacturing as well as information systems and strategic management. This fields is related to engineering management, operations management, service management and systems engineering. In the context of software


id: human-performance-modeling-20260505-0
file: data/en.wikipedia.org/wiki/Human_performance_modeling-0.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
Human performance modeling (HPM) is a method of quantifying human behavior, cognition, and processes. It is a tool used by human factors researchers and practitioners for both the analysis of human function and for the development of systems designed for optimal user experience and interaction . It is a complementary approach to other usability testing methods for evaluating the impact of interface features on operator performance. == History == The Human Factors and Ergonomics Society (HFES) formed the Human Performance Modeling Technical Group in 2004. Although a recent discipline, human factors practitioners have been constructing and applying models of human performance since World War II. Notable early examples of human performance models include Paul Fitts' model of aimed motor movement (1954), the choice reaction time models of Hick (1952) and Hyman (1953), and the Swets et al. (1964) work on signal detection. It is suggested that the earliest developments in HPM arose out of the need to quantify human-system feedback for those military systems in development during WWII (see Manual Control Theory below), with continued interest in the development of these models augmented by the cognitive revolution (see Cognition & Memory below). == Human Performance Models == Human performance models


id: human-performance-modeling-20260505-1
file: data/en.wikipedia.org/wiki/Human_performance_modeling-1.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
==== Manual Control Theory ==== Complex motor tasks, such as those carried out by musicians and athletes, are not well modeled due to their complexity. Human target-tracking behavior, however, is one complex motor task that is an example of successful HPM. The history of manual control theory is extensive, dating back to the 1800s in regard to the control of water clocks. However, during the 1940s with the innovation of servomechanisms in WWII, extensive research was put into the continuous control and stabilization of contemporary systems such as radar antennas, gun turrets, and ships/aircraft via feedback control signals. Analysis methods were developed that predicted the required control systems needed to enable stable, efficient control of these systems (James, Nichols, & Phillips, 1947). Originally interested in temporal response - the relationship between sensed output and motor output as a function of time - James et al. (1947) discovered that the properties of such systems are best characterized by understanding temporal response after it had been transformed into a frequency response; a ratio of output to input amplitude and lag in response over the range of frequencies to which they are sensitive. For systems that respond linearly to these inputs, the frequency


id: human-performance-modeling-20260505-2
file: data/en.wikipedia.org/wiki/Human_performance_modeling-2.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
==== Visual Sampling ==== Many domains contain multiple displays, and require more than a simple discrete yes/no response time measurement. A critical question for these situations may be "How much time will operators spend looking at X relative to Y?" or "What is the likelihood that the operator will completely miss seeing a critical event?" Visual sampling is the primary means of obtaining information from the world. An early model in this domain is Sender's (1964, 1983) based upon operators monitoring of multiple dials, each with different rates of change. Operators try, as best as they can, to reconstruct the original set of dials based on discrete sampling. This relies on the mathematical Nyquist theorem stating that a signal at W Hz can be reconstructed by sampling every 1/W seconds. This was combined with a measure of the information generation rate for each signal, to predict the optimal sampling rate and dwell time for each dial. Human limitations prevent human performance from matching optimal performance, but the predictive power of the model influenced future work in this area, such as Sheridan's (1970) extension of the model with considerations of access cost and information sample value. A modern conceptualization by Wickens


id: human-performance-modeling-20260505-3
file: data/en.wikipedia.org/wiki/Human_performance_modeling-3.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
==== Workload ==== Although an exact definition or method for measurement of the construct of workload is debated by the human factors community, a critical part of the notion is that human operators have some capacity limitations and that such limitations can be exceeded only at the risk of degrading performance. For physical workload, it may be understood that there is a maximum amount that a person should be asked to lift repeatedly, for example. However, the notion of workload becomes more contentious when the capacity to be exceeded is in regard to attention - what are the limits of human attention, and what exactly is meant by attention? Human performance modeling produces valuable insights into this area. Byrne and Pew (2009) consider an example of a basic workload question: "To what extent do task A and B interfere?" These researchers indicate this as the basis for the psychological refractory period (PRP) paradigm. Participants perform two choice reaction-time tasks, and the two tasks will interfere to a degree - especially when the participant must react to the stimuli for the two tasks when they are close together in time - but the degree of interference is typically smaller than the


id: human-performance-modeling-20260505-4
file: data/en.wikipedia.org/wiki/Human_performance_modeling-4.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
==== Routine Cognitive Skill ==== One area of memory and cognition regards modeling routine cognitive skills; when an operator has the correct knowledge of how to perform a task and simply needs to execute that knowledge. This is widely applicable, as many operators are practiced enough that their procedures become routine. The GOMS (goals, operators, methods, and selection rules) family of Human Performance Models popularized and well-defined by researchers in the field (Card et al., 1983; John & Kieras, 1996a, 1996b) were originally applied to model users of computer interfaces, but have since been extended to other areas. They are useful HPM tools, suitable for a variety of different concerns and sizes of analysis, but are limited in regard to analyzing user error (see Wood & Kieras, 2002, for an effort to extend GOMS to handling errors). The simplest form of a GOMS model is a keystroke-level model (KLM) - in which all physical actions are listed (e.g., keystrokes, mouse clicks), also termed operations, that a user must take in order to complete a given task. Mental operations (e.g., find an object on the screen) augment this using a straightforward set of rules. Each operations has a time associated with


id: human-performance-modeling-20260505-5
file: data/en.wikipedia.org/wiki/Human_performance_modeling-5.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
=== Integrated Models === Many of these models described are very limited in their application. Although many extensions of SDT have been proposed to cover a variety of other judgement domains (see T.D. Wickens, 2002, for examples), most of these never caught on, and SDT remains limited to binary situations. The narrow scope of these models is not limited to human factors, however - Newton's laws of motion have little predictive power regarding electromagnetism, for example. However, this is frustrating for human factors professionals, because real human performance in vivo draws upon a wide array of human capabilities. As Byrne & Pew (2009) describe, "in the space of a minute, a pilot might quite easily conduct a visual search, aim for and push a button, execute a routine procedure, make a multiple-cue probabilistic judgement" and do just about everything else described by fundamental human performance models. A fundamental review of HPM by the National Academies (Elkind, Card, Hochberg, & Huey, 1990) described integration as the great unsolved challenge in HPM. This issue remains to be solved, however, there have been efforts to integrate and unify multiple models and build systems that span across domains. In human factors, the two primary


id: human-performance-modeling-20260505-6
file: data/en.wikipedia.org/wiki/Human_performance_modeling-6.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
==== Cognitive Architectures ==== Cognitive Architectures are broad theories of human cognition based on a wide selection of human empirical data and are generally implemented as computer simulations. They are the embodiment of a scientific hypothesis about those aspects of human cognition relatively constant over time and independent of task (Gray, Young, & Kirschenbaum, 1997; Ritter & young, 2001). Cognitive architectures are an attempt to theoretically unify disconnected empirical phenomena in the form of computer simulation models. While theory is inadequate for the application of human factors, since the 1990s cognitive architectures also include mechanisms for sensation, perception, and action. Two early examples of this include the Executive Process Interactive Control model (EPIC; Kieras, Wood, & Meyer, 1995; Meyer & Kieras, 1997) and the ACT-R (Byrne & Anderson, 1998). A model of a task in a cognitive architecture, generally referred to as a cognitive model, consists of both the architecture and the knowledge to perform the task. This knowledge is acquired through human factors methods including task analyses of the activity being modeled. Cognitive architectures are also connected with a complex simulation of the environment in which the task is to be performed - sometimes, the architecture interacts directly with


id: human-performance-modeling-20260505-7
file: data/en.wikipedia.org/wiki/Human_performance_modeling-7.md
category: reference
title: Human performance modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Human_performance_modeling
date_saved: 2026-05-05T10:00:54.973981+00:00
instance: kb-cron
parent: human-performance-modeling-20260505-0
summary:
=== Misconceptions === Many human performance models share key features with Artificial Intelligence (AI) methods and systems. The function of AI research is to produce systems that exhibit intelligent behavior, generally without consideration of the degree to which that intelligence resembles or predicts human performance, yet the distinction between AI methods and that of HPM is at times unclear. For example, Bayesian classifiers used to filter spam emails approximate human classification performance (classifying spam emails as spam, and non-spam emails as importation) and are thus highly intelligence systems, but fail to rely on interpretation of the semantics of the messages themselves; instead relying on statistical methods. However, Bayesian analysis can also be essential to human performance models. === Usefulness === Models may focus more on the processes involved in human performance rather than the products of human performance, thus limiting their usefulness in human factors practice. === Abstraction === The abstraction necessary for understandable models competes with accuracy. While generality, simplicity, and understandability are important to the application of models in human factors practice, many valuable human performance models are inaccessible to those without graduate, or postdoctoral training. For example, while Fitts's law is straightforward for even undergraduates, the lens


id: integrated-assessment-modelling-20260505-0
file: data/en.wikipedia.org/wiki/Integrated_assessment_modelling-0.md
category: reference
title: Integrated assessment modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_assessment_modelling
date_saved: 2026-05-05T10:00:56.130150+00:00
instance: kb-cron
parent: integrated-assessment-modelling-20260505-0
summary:
Integrated assessment modelling (IAM) or integrated modelling (IM) is a term used for a type of scientific modelling that tries to link main features of society and economy with the biosphere and atmosphere into one modelling framework. The goal of integrated assessment modelling is to accommodate informed policy-making, usually in the context of climate change though also in other areas of human and social development. While the detail and extent of integrated disciplines varies strongly per model, all climatic integrated assessment modelling includes economic processes as well as processes producing greenhouse gases. Other integrated assessment models also integrate other aspects of human development such as education, health, infrastructure, and governance. These models are integrated because they span multiple academic disciplines, including economics and climate science and for more comprehensive models also energy systems, land-use change, agriculture, infrastructure, conflict, governance, technology, education, and health. The word assessment comes from the use of these models to provide information for answering policy questions. To quantify these integrated assessment studies, numerical models are used. Integrated assessment modelling does not provide predictions for the future but rather estimates what possible scenarios look like. There are different types of integrated assessment models. One classification distinguishes between


id: integrated-asset-modelling-20260505-0
file: data/en.wikipedia.org/wiki/Integrated_asset_modelling-0.md
category: reference
title: Integrated asset modelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_asset_modelling
date_saved: 2026-05-05T10:00:57.298855+00:00
instance: kb-cron
parent: integrated-asset-modelling-20260505-0
summary:
Integrated asset modelling (IAM) is the generic term used in the oil industry for computer modelling of both the subsurface and the surface elements of a field development. Historically the reservoir has always been modelled separately from the surface network and the facilities. In order to capture the interaction between those two or more standalone models, several time-consuming iterations were required. For example, a change in the water breakthrough leads to a change in the deliverability of the surface network which in turn leads to a production acceleration or deceleration in the reservoir. In order to go through this lengthy process more quickly, the industry has slowly been adopting a more integrated approach which captures the constraints imposed by the infrastructure on the network immediately. == Basis == As the aim of an IAM is to provide a production forecast which honours both the physical realities of the reservoir and the infrastructure it needs to contain the following elements; A pressure network A subsurface saturation model An availability model A constraint manager A production optimisation algorithm Some but not all models also contain an economics and risk model component so that the IAM can be used for economic evaluation. ==


id: knowledge-representation-and-reasoning-20260505-0
file: data/en.wikipedia.org/wiki/Knowledge_representation_and_reasoning-0.md
category: reference
title: Knowledge representation and reasoning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Knowledge_representation_and_reasoning
date_saved: 2026-05-05T10:00:58.436297+00:00
instance: kb-cron
parent: knowledge-representation-and-reasoning-20260505-0
summary:
Knowledge representation (KR) aims to model information in a structured manner to formally represent it as knowledge in knowledge-based systems whereas knowledge representation and reasoning (KRR, KR&R, or KR²) also aims to understand, reason, and interpret knowledge. KRR is widely used in the field of artificial intelligence (AI) with the goal of representing information about the world in a form that a computer system can use to solve complex tasks, such as diagnosing a medical condition or having a natural-language dialog. KR incorporates findings from psychology about how humans solve problems and represent knowledge, in order to design formalisms that make complex systems easier to design and build. KRR also incorporates findings from logic to automate various kinds of reasoning. Traditional KRR focuses more on the declarative representation of knowledge. Related knowledge representation formalisms mainly include vocabularies, thesaurus, semantic networks, axiom systems, frames, rules, logic programs, and ontologies. Examples of automated reasoning engines include inference engines, theorem provers, model generators, and classifiers. In a broader sense, parameterized models in machine learning — including neural network architectures such as convolutional neural networks and transformers — can also be regarded as a family of knowledge representation formalisms. The question of which formalism


id: knowledge-representation-and-reasoning-20260505-1
file: data/en.wikipedia.org/wiki/Knowledge_representation_and_reasoning-1.md
category: reference
title: Knowledge representation and reasoning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Knowledge_representation_and_reasoning
date_saved: 2026-05-05T10:00:58.436297+00:00
instance: kb-cron
parent: knowledge-representation-and-reasoning-20260505-0
summary:
The earliest work in computerized knowledge representation was focused on general problem-solvers such as the General Problem Solver (GPS) system developed by Allen Newell and Herbert A. Simon in 1959 and the Advice Taker proposed by John McCarthy also in 1959. GPS featured data structures for planning and decomposition. The system would begin with a goal. It would then decompose that goal into sub-goals and then set out to construct strategies that could accomplish each subgoal. The Advisor Taker, on the other hand, proposed the use of the predicate calculus to implement common sense reasoning. Many of the early approaches to knowledge representation in Artificial Intelligence (AI) used graph representations and semantic networks, similar to knowledge graphs today. In such approaches, problem solving was a form of graph traversal or path-finding, as in the A* search algorithm. Typical applications included robot plan-formation and game-playing. Other researchers focused on developing automated theorem-provers for first-order logic, motivated by the use of mathematical logic to formalise mathematics and to automate the proof of mathematical theorems. A major step in this direction was the development of the resolution method by John Alan Robinson. In the meanwhile, John McCarthy and Pat Hayes developed the situation


id: knowledge-representation-and-reasoning-20260505-2
file: data/en.wikipedia.org/wiki/Knowledge_representation_and_reasoning-2.md
category: reference
title: Knowledge representation and reasoning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Knowledge_representation_and_reasoning
date_saved: 2026-05-05T10:00:58.436297+00:00
instance: kb-cron
parent: knowledge-representation-and-reasoning-20260505-0
summary:
Any mechanically embodied intelligent process will be comprised of structural ingredients that a) we as external observers naturally take to represent a propositional account of the knowledge that the overall process exhibits, and b) independent of such external semantic attribution, play a formal but causal and essential role in engendering the behavior that manifests that knowledge. One of the most active areas of knowledge representation research is the Semantic Web. The Semantic Web seeks to add a layer of semantics (meaning) on top of the current Internet. Rather than indexing web sites and pages via keywords, the Semantic Web creates large ontologies of concepts. Searching for a concept will be more effective than traditional text only searches. Frame languages and automatic classification play a big part in the vision for the future Semantic Web. The automatic classification gives developers technology to provide order on a constantly evolving network of knowledge. Defining ontologies that are static and incapable of evolving on the fly would be very limiting for Internet-based systems. The classifier technology provides the ability to deal with the dynamic environment of the Internet. Recent projects funded primarily by the Defense Advanced Research Projects Agency (DARPA) have integrated frame languages


id: knowledge-representation-and-reasoning-20260505-3
file: data/en.wikipedia.org/wiki/Knowledge_representation_and_reasoning-3.md
category: reference
title: Knowledge representation and reasoning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Knowledge_representation_and_reasoning
date_saved: 2026-05-05T10:00:58.436297+00:00
instance: kb-cron
parent: knowledge-representation-and-reasoning-20260505-0
summary:
"A knowledge representation (KR) is most fundamentally a surrogate, a substitute for the thing itself, used to enable an entity to determine consequences by thinking rather than acting," i.e., "by reasoning about the world rather than taking action in it." "It is a set of ontological commitments", i.e., "an answer to the question: In what terms should I think about the world?" "It is a fragmentary theory of intelligent reasoning, expressed in terms of three components: (i) the representation's fundamental conception of intelligent reasoning; (ii) the set of inferences the representation sanctions; and (iii) the set of inferences it recommends." "It is a medium for pragmatically efficient computation", i.e., "the computational environment in which thinking is accomplished. One contribution to this pragmatic efficiency is supplied by the guidance a representation provides for organizing information" so as "to facilitate making the recommended inferences." "It is a medium of human expression", i.e., "a language in which we say things about the world." Knowledge representation and reasoning are a key enabling technology for the Semantic Web. Languages based on the Frame model with automatic classification provide a layer of semantics on top of the existing Internet. Rather than searching via text strings as


id: knowledge-representation-and-reasoning-20260505-4
file: data/en.wikipedia.org/wiki/Knowledge_representation_and_reasoning-4.md
category: reference
title: Knowledge representation and reasoning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Knowledge_representation_and_reasoning
date_saved: 2026-05-05T10:00:58.436297+00:00
instance: kb-cron
parent: knowledge-representation-and-reasoning-20260505-0
summary:
Primitives. What is the underlying framework used to represent knowledge? Semantic networks were one of the first knowledge representation primitives. Also, data structures and algorithms for general fast search. In this area, there is a strong overlap with research in data structures and algorithms in computer science. In early systems, the Lisp programming language, which was modeled after the lambda calculus, was often used as a form of functional knowledge representation. Frames and Rules were the next kind of primitive. Frame languages had various mechanisms for expressing and enforcing constraints on frame data. All data in frames are stored in slots. Slots are analogous to relations in entity-relation modeling and to object properties in object-oriented modeling. Another technique for primitives is to define languages that are modeled after First Order Logic (FOL). The most well known example is Prolog, but there are also many special-purpose theorem-proving environments. These environments can validate logical models and can deduce new theories from existing models. Essentially they automate the process a logician would go through in analyzing a model. Theorem-proving technology had some specific practical applications in the areas of software engineering. For example, it is possible to prove that a software program rigidly


id: knowledge-representation-and-reasoning-20260505-5
file: data/en.wikipedia.org/wiki/Knowledge_representation_and_reasoning-5.md
category: reference
title: Knowledge representation and reasoning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Knowledge_representation_and_reasoning
date_saved: 2026-05-05T10:00:58.436297+00:00
instance: kb-cron
parent: knowledge-representation-and-reasoning-20260505-0
summary:
In the early years of knowledge-based systems the knowledge-bases were fairly small. The knowledge-bases that were meant to actually solve real problems rather than do proof of concept demonstrations needed to focus on well defined problems. So for example, not just medical diagnosis as a whole topic, but medical diagnosis of certain kinds of diseases. As knowledge-based technology scaled up, the need for larger knowledge bases and for modular knowledge bases that could communicate and integrate with each other became apparent. This gave rise to the discipline of ontology engineering, designing and building large knowledge bases that could be used by multiple projects. One of the leading research projects in this area was the Cyc project. Cyc was an attempt to build a huge encyclopedic knowledge base that would contain not just expert knowledge but common-sense knowledge. In designing an artificial intelligence agent, it was soon realized that representing common-sense knowledge, knowledge that humans simply take for granted, was essential to make an AI that could interact with humans using natural language. Cyc was meant to address this problem. The language they defined was known as CycL. After CycL, a number of ontology languages have been developed. Most are declarative


id: metamodeling-20260505-0
file: data/en.wikipedia.org/wiki/Metamodeling-0.md
category: reference
title: Metamodeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Metamodeling
date_saved: 2026-05-05T10:00:59.634578+00:00
instance: kb-cron
parent: metamodeling-20260505-0
summary:
A metamodel is a model of a model, and metamodeling is the process of generating such metamodels. Thus metamodeling or meta-modeling is the analysis, construction, and development of the frames, rules, constraints, models, and theories applicable and useful for modeling a predefined class of problems. As its name implies, this concept applies the notions of meta- and modeling in software engineering and systems engineering. Metamodels are of many types and have diverse applications. == Overview == A metamodel/ surrogate model is a model of the model, i.e. a simplified model of an actual model of a circuit, system, or software-like entity. Metamodel can be a mathematical relation or algorithm representing input and output relations. A model is an abstraction of phenomena in the real world; a metamodel is yet another abstraction, highlighting the properties of the model itself. A model conforms to its metamodel in the way that a computer program conforms to the grammar of the programming language in which it is written. Various types of metamodels include polynomial equations, neural networks, Kriging, etc. "Metamodeling" is the construction of a collection of "concepts" (things, terms, etc.) within a certain domain. Metamodeling typically involves studying the output and input relationships


id: mixture-theory-20260505-0
file: data/en.wikipedia.org/wiki/Mixture_theory-0.md
category: reference
title: Mixture theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mixture_theory
date_saved: 2026-05-05T10:01:00.780760+00:00
instance: kb-cron
parent: mixture-theory-20260505-0
summary:
Mixture theory is used to model multiphase systems using the principles of continuum mechanics generalised to several interpenetrable continua. The basic assumption is that, at any instant of time, all phases are present at every material point, and momentum and mass balance equations are postulated. Like other models, mixture theory requires constitutive relations to close the system of equations. Krzysztof Wilmanski extended the model by introducing a balance equation of porosity. == References ==


id: model-dependent-realism-20260505-0
file: data/en.wikipedia.org/wiki/Model-dependent_realism-0.md
category: reference
title: Model-dependent realism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Model-dependent_realism
date_saved: 2026-05-05T10:01:01.927550+00:00
instance: kb-cron
parent: model-dependent-realism-20260505-0
summary:
Model-dependent realism is a view of scientific inquiry that focuses on the role of scientific models of phenomena. It claims reality should be interpreted based upon these models, and where several models overlap in describing a particular subject, multiple, equally valid, realities exist. It claims that it is meaningless to talk about the "true reality" of a model as we can never be absolutely certain of anything. The only meaningful thing is the usefulness of the model. The term "model-dependent realism" was coined by Stephen Hawking and Leonard Mlodinow in their 2010 book The Grand Design. == Overview == Model-dependent realism asserts that all we can know about "reality" consists of networks of world pictures that explain observations by connecting them by rules to concepts defined in models. Will an ultimate theory of everything be found? Hawking and Mlodinow suggest it is unclear: In the history of science we have discovered a sequence of better and better theories or models, from Plato to the classical theory of Newton to modern quantum theories. It is natural to ask: Will this sequence eventually reach an end point, an ultimate theory of the universe, that will include all forces and predict every observation


id: modeling-perspective-20260505-0
file: data/en.wikipedia.org/wiki/Modeling_perspective-0.md
category: reference
title: Modeling perspective
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Modeling_perspective
date_saved: 2026-05-05T10:01:03.065120+00:00
instance: kb-cron
parent: modeling-perspective-20260505-0
summary:
A modeling perspective in information systems is a particular way to represent pre-selected aspects of a system. Any perspective has a different focus, conceptualization, dedication and visualization of what the model is representing. The traditional way to distinguish between modeling perspectives is structural, functional and behavioral/processual perspectives. This together with rule, object, communication and actor and role perspectives is one way of classifying modeling approaches. == Types of perspectives == === Structural modeling perspective === This approach concentrates on describing the static structure. The main concept in this modeling perspective is the entity, this could be an object, phenomena, concept, thing etc. The data modeling languages have traditionally handled this perspective, examples of such being: The ER-language (Entity-Relationship) Generic Semantic Modeling language (GSM) Other approaches including: The NIAM language (Binary relationship language) Conceptual graphs (Sowa) Looking at the ER-language we have the basic components: Entities: Distinctively identifiable phenomenon. Relationships: An association among the entities. Attributes: Used to give value to a property of an entity/relationship. Looking at the generic semantic modeling language we have the basic components: Constructed types built by abstraction: Aggregation, generalization, and association. Attributes. Primitive types: Data types in GSM are classified into printable and abstract types.


id: nexus-tools-platform-20260505-0
file: data/en.wikipedia.org/wiki/Nexus_Tools_Platform-0.md
category: reference
title: Nexus Tools Platform
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Nexus_Tools_Platform
date_saved: 2026-05-05T10:01:04.200363+00:00
instance: kb-cron
parent: nexus-tools-platform-20260505-0
summary:
The Nexus Tools Platform or NTP is a web-based inventory platform that allows an interactive comparison of environmental models in a statistical way. Developed by the UNU Institute for Integrated Management of Material Fluxes and of Resources (UNU-FLORES), the platform helps a user to analyze existing modelling tools related to environmental resource management and associated nexus perspectives, such as a Water-Energy-Food Nexus. As a result, the user can select the most appropriate tools to fit the research needs. == Integrated Resources Management (Nexus Approach) == Considering an increase in the global population, the demand for both food and water is expected to grow by more than 50% by 2050. At the same time, agricultural activity already puts significant stress on the quantity and quality of soils and freshwater resources worldwide. This leads to growing rates of land degradation and ecosystem deterioration. Long-term solutions to those challenges require integrated management of environmental resources which can be also referred to as a Nexus Approach. This approach focuses on the synergies between sectors in order to minimize trade-offs, increase resource use efficiency, and improve environmental policy & governance which is crucial for the achievement of the Sustainable Development Goals. For example, the sustainable


id: participatory-modeling-20260505-0
file: data/en.wikipedia.org/wiki/Participatory_modeling-0.md
category: reference
title: Participatory modeling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_modeling
date_saved: 2026-05-05T10:01:05.335906+00:00
instance: kb-cron
parent: participatory-modeling-20260505-0
summary:
Participatory modeling is a purposeful learning process for action that engages the implicit and explicit knowledge of stakeholders to create formalized and shared representation(s) of reality. In this process, the participants co-formulate the problem and use modeling practices to aid in the description, solution, and decision-making actions of the group. Participatory modeling is often used in environmental and resource management contexts. It can be described as engaging non-scientists in the scientific process. The participants structure the problem, describe the system, and create a shared understanding of how the system works. This can further lead to more quantitative analyses, and may sometimes result in a computer model of the system, which is then jointly used to test policy interventions, and propose one or more solutions. Participatory modeling is often used in natural resources management, such as forests or water. There are numerous benefits from this type of modeling, including a high degree of ownership and motivation towards change for the people involved in the modeling process. It also helps to develop more acceptable solutions and often creates more consensus among the stakeholders involved. == See also == Model-driven architecture Participatory design Participatory GIS Public participation GIS Problem structuring methods Shared vision


id: performance-and-modelling-of-ac-transmission-20260505-0
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-0.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
Modelling of a transmission line is done to analyse its performance and characteristics. The gathered information vis simulating the model can be used to reduce losses or to compensate these losses. Moreover, it gives more insight into the working of transmission lines and helps to find a way to improve the overall transmission efficiency with minimum cost. == Performance modelling == Performance modelling is the abstraction of a real system into a simplified representation to enable the prediction of performance. The creation of a model can provide insight into how a proposed or actual system will or does work. This can, however, point towards different things to people belonging to different fields of work. Performance modelling has many benefits, which includes: Relatively inexpensive prediction of future performance. A clearer understanding of a system's performance characteristics. Additionally it may include, a mechanism for risk management and reduction with design support for future projects. A model will often be created specifically so that it can be interpreted by a software tool that simulates the system's behaviour, based on the information contained in the performance model. Such tools provide further insight into the system's behaviour and can be used to identify bottlenecks or


id: performance-and-modelling-of-ac-transmission-20260505-1
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-1.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
In electrical engineering, the power factor of an AC electrical power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit, and is a dimensionless number in the closed interval of −1 to 1. A power factor of less than one indicates the voltage and current are not in phase, reducing the instantaneous product of the two. A negative power factor occurs when the device (which is normally the load) generates power, which then flows back towards the source. Real power is the instantaneous product of voltage and current and represents the capacity of the electricity for performing work. Apparent power is the average product of current and voltage. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power may be greater than the real power(pf ≤0.5). In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. The higher currents increase energy loss in


id: performance-and-modelling-of-ac-transmission-20260505-2
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-2.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
==== Phase constant ==== The imaginary part of the propagation constant is the phase constant and is denoted by Greek lowercase letter β (beta). It causes the signal phase to shift along a transmission line. Generally denoted in radians per meter (rad/m). The propagation constant is denoted by Greek lowercase letter γ (gamma), and γ = α + jβ === Voltage Regulation === Voltage regulation is a measure of the change in the voltage magnitude between the sending and receiving end of a component, such as a transmission or distribution line. It is given in percentage for different lines. Mathematically, voltage regulation is given by, V . R = V n o − l o a d − V f u l l − l o a d V n o − l o a d {\displaystyle V.R={\frac {V_{no-load}-V_{full-load}}{V_{no-load}}}} == Line parameters of AC transmission == The AC transmission has four line parameters, these are the series resistance & inductance, and shunt capacitance and admittance. These parameters are responsible for distinct behavior of voltage and current waveforms along the transmission line. Line parameters are generally represented in their respective units per km of length in transmission lines. So these parameters


id: performance-and-modelling-of-ac-transmission-20260505-3
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-3.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
L = μ 0 2 π l n D G M D r ′ H / m {\displaystyle L={\frac {\mu _{0}}{2\pi }}ln{\frac {D_{GMD}}{r\prime }}H/m} . Where, D G M D {\displaystyle D_{GMD}} is the geometric mean distance in between the conductors. If the lines are not properly transposed, the inductances become unequal and contain imaginary terms due to mutual inductances. In case of proper transposition, all the conductors occupy the available positions equal distance and thus the imaginary terms are cancelled out. And all the line inductances become equal. === Shunt capacitance === ==== Definition ==== Capacitance is the ratio of the change in an electric charge in a system to the corresponding change in its electric potential. The capacitance is a function only of the geometry of the design (e.g. area of the plates and the distance between them) and the permittivity of the dielectric material between the plates of the capacitor. For many dielectric materials, the permittivity and thus the capacitance is independent of the potential difference between the conductors and the total charge on them. The SI unit of capacitance is the farad (F). A 1 farad capacitor, when charged with 1 coulomb of electrical charge, has


id: performance-and-modelling-of-ac-transmission-20260505-4
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-4.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
A two-port network (a kind of four-terminal network or quadripole) is an electrical network (circuit) or device with two pairs of terminals to connect to external circuits. Two terminals constitute a port if the currents applied to them satisfy the essential requirement known as the port condition: the electric current entering one terminal must equal the current emerging from the other terminal on the same port. The ports constitute interfaces where the network connects to other networks, the points where signals are applied or outputs are taken. In a two-port network, often port 1 is considered the input port and port 2 is considered the output port. The two-port network model is used in mathematical circuit analysis techniques to isolate portions of larger circuits. A two-port network is regarded as a "black box" with its properties specified by a matrix of numbers. This allows the response of the network to signals applied to the ports to be calculated easily, without solving for all the internal voltages and currents in the network. It also allows similar circuits or devices to be compared easily. For example, transistors are often regarded as two-ports, characterized by their h-parameters (see below) which are listed by


id: performance-and-modelling-of-ac-transmission-20260505-5
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-5.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
=== Basis of classification === ==== Derivation of voltage\current wavelength ==== Current and voltage propagate in a transmission line with a speed equal to the speed of light (c) i.e. appx. 3 × 10 8 m / s e c = 3 × 10 5 k m / s e c {\displaystyle 3\times 10^{8}m/sec=3\times 10^{5}km/sec} and the frequency (f) of voltage or current is 50 Hz ( although in the America and parts of Asia it is typically 60 Hz) Therefore, wavelength (λ) can be calculated as below : f λ = c {\displaystyle f\lambda =c} or, λ = c f {\displaystyle \lambda ={\frac {c}{f}}} or, λ = 3 × 10 5 50 = 6000 K m {\displaystyle \lambda ={\frac {3\times 10^{5}}{50}}=6000Km} ==== Reason behind classification ==== A transmission line with 60 km of length is very very small( 1 100 {\displaystyle {\tfrac {1}{100}}} times) when compared with wavelength i.e. 6000 km. Up to 240 km ( 1 25 {\displaystyle {\tfrac {1}{25}}} times of wavelength) (250 km is taken for easy remembering) length of the line, current or voltage waveform is so small that it can be approximated to a straight line for all practical purposes. For line length of


id: performance-and-modelling-of-ac-transmission-20260505-6
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-6.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
I 1 & I 3 {\displaystyle I_{1}\&I_{3}} are the currents through the shunt capacitances at the sending and receiving end respectively whereas I 2 {\displaystyle I_{2}} is the current through the series impedance. Again, V S = Z I 2 + V R = Z ( V R Y 2 + I R ) + V R {\displaystyle V_{S}=ZI_{2}+V_{R}=Z(V_{R}{\frac {Y}{2}}+I_{R})+V_{R}} or, So, by substituting we get : I S = Y 2 [ ( 1 + Y Z 2 ) V R + Z I R ] + Y 2 V R + I R {\displaystyle I_{S}={\frac {Y}{2}}[(1+{\frac {YZ}{2}})V_{R}+ZI_{R}]+{\frac {Y}{2}}V_{R}+I_{R}} or, The equation obtained thus, eq(4) & (5) can be written into matrix form as follows : so, the ABCD parameters are : A = D = ( 1 + Y Z 2 ) {\displaystyle (1+{\frac {YZ}{2}})} per unit B =Z Ω C = Y ( 1 + Y Z 4 ) ℧ {\displaystyle Y(1+{\frac {YZ}{4}})\mho } === Nominal T representation === In the nominal T model of a medium transmission line, the net series impedance is divided into two halves and placed on either side of the lumped shunt admittance i.e. placed in the middle. The circuit so formed


id: performance-and-modelling-of-ac-transmission-20260505-7
file: data/en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission-7.md
category: reference
title: Performance and modelling of AC transmission
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Performance_and_modelling_of_AC_transmission
date_saved: 2026-05-05T10:01:06.523639+00:00
instance: kb-cron
parent: performance-and-modelling-of-ac-transmission-20260505-0
summary:
V r − Z c I r 2 e − γ l {\displaystyle {\frac {V_{r}-Z_{c}I_{r}}{2}}e^{-\gamma l}} is called reflected voltage wave We can rewrite the eq.(22) & eq.(23) as, So, by considering the corresponding analogy for long transmission line, the obtained equations i.e. eq.(24) eq.(25) can be written into matrix form as follows: The ABCD parameters are given by : A = D = cosh ⁡ γ l {\displaystyle \cosh \gamma l} B = Z c sinh ⁡ γ l {\displaystyle Z_{c}\sinh \gamma l} C = sinh ⁡ γ l Z c {\displaystyle {\frac {\sinh \gamma l}{Z_{c}}}} ==== Π Representation approach ==== Like the medium transmission line, the long line can also be approximated into an equivalent Π representation. In the Π-equivalent of a long transmission line, the series impedance is denoted by Z′ while the shunt admittance is denoted by Y′. So, the ABCD parameters of this long line can be defined like medium transmission line as : A = D = ( 1 + Y ′ Z ′ 2 ) {\displaystyle (1+{\frac {Y\prime Z\prime }{2}})} per unit B = Z′ Ω C = Y ( 1 + Y ′ Z ′ 4 ) ℧ {\displaystyle Y(1+{\frac {Y\prime Z\prime


id: process-map-20260505-0
file: data/en.wikipedia.org/wiki/Process_map-0.md
category: reference
title: Process map
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Process_map
date_saved: 2026-05-05T10:01:07.708970+00:00
instance: kb-cron
parent: process-map-20260505-0
summary:
Process map is a global-system process model that is used to outline the processes that make up the business system and how they interact with each other. Process map shows the processes as objects, which means it is a static and non-algorithmic view of the processes. It should be differentiated from a detailed process model, which shows a dynamic and algorithmic view of the processes, usually known as a process flow diagram. There are different notation standards that can be used for modelling process maps, but the most notable ones are TOGAF Event Diagram, Eriksson-Penker notation, and ARIS Value Added Chain. == Global process models == Global characteristics of the business system are captured by global or system models. Global process models are presented using different methodologies and sometimes under different names. Most notably, they are named process map in Visual Paradigm and MMABP, value-added chain in ARIS, and process diagram in Eriksson-Penker notation – which can easily lead to the confusion with process flow (detailed process model). Global models are mainly object-oriented and present a static view of the business system; they do not describe dynamic aspects of processes. A process map shows the presence of processes and their


id: process-map-20260505-1
file: data/en.wikipedia.org/wiki/Process_map-1.md
category: reference
title: Process map
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Process_map
date_saved: 2026-05-05T10:01:07.708970+00:00
instance: kb-cron
parent: process-map-20260505-0
summary:
=== Eriksson-Penker Diagram === Eriksson-Penker diagram is a tool used in business model analysis and design. It is named after Hans-Erik Eriksson and Magnus Penker, who developed the concept in their book "Business modelling with UML: Business Patterns at Work”. Eriksson-Penker diagrams are used to map out the key components of a business model and how they interact with one another. The diagrams typically consist of a series of boxes and lines that represent the different elements of the business model, such as the value proposition, customer segments, channels, revenue streams, and key resources. The lines between the boxes represent the relationships and dependencies between the different elements of the business model. These diagrams are useful for visualizing and understanding the various components of a business model, and can help organizations identify potential areas for improvement or areas of risk. They can also be used as a communication tool to help stakeholders understand the business model and its underlying assumptions. These diagrams are useful for visualizing and understanding the various components of a business model, and can help organizations identify potential areas for improvement or areas of risk. They can also be used as a communication tool to help stakeholders


id: quantitative-storytelling-20260505-0
file: data/en.wikipedia.org/wiki/Quantitative_storytelling-0.md
category: reference
title: Quantitative storytelling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantitative_storytelling
date_saved: 2026-05-05T10:01:09.221216+00:00
instance: kb-cron
parent: quantitative-storytelling-20260505-0
summary:
Quantitative storytelling (QST) is a systematic approach to exploring the many frames potentially legitimate in a scientific study or controversy. QST assumes that, in an interconnected society, multiple frameworks and worldviews are legitimately upheld by different entities and social actors. QST looks critically at models used in evidence-based policy. Such models are often reductionist in that tractability (i.e. the possibility of proceeding towards a solution to a given problem) is achieved at the expense of suppressing available evidence. QST suggests corrective approaches to this practice. == Description == Quantitative storytelling (QST) addresses evidence-based policy and can be considered a reaction to methods of quantification with cost-benefit analysis or risk analysis. Jerome Ravetz and Steve Rayner discuss the concept that some of the evidence needed for policy is removed from view. They suggest that 'uncomfortable knowledge' is subtracted from the policy discourse with the objective of easing tractability or to advance a given agenda. The word 'hypo-cognition' has been used in the context of these instrumental uses of frames. According to Rayner, a phenomenon of "displacement" takes place when a model becomes the objective instead of the tool, for example, when an institution chooses to monitor and manage the outcome of


id: specification-language-20260505-0
file: data/en.wikipedia.org/wiki/Specification_language-0.md
category: reference
title: Specification language
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Specification_language
date_saved: 2026-05-05T10:01:10.410130+00:00
instance: kb-cron
parent: specification-language-20260505-0
summary:
A specification language is a formal language in computer science used during systems analysis, requirements analysis, and systems design to describe a system at a much higher level than a programming language, which is used to produce the executable code for a system. == Overview == Specification languages are generally not directly executed. They are meant to describe the what, not the how. It is considered an error if a requirement specification is cluttered with unnecessary implementation detail. A common fundamental assumption of many specification approaches is that programs are modelled as algebraic or model-theoretic structures that include a collection of sets of data values together with functions over those sets. This level of abstraction coincides with the view that the correctness of the input/output behaviour of a program takes precedence over all its other properties. In the property-oriented approach to specification (taken e.g. by CASL), specifications of programs consist mainly of logical axioms, usually in a logical system in which equality has a prominent role, describing the properties that the functions are required to satisfy—often just by their interrelationship. This is in contrast to so-called model-oriented specification in frameworks like VDM and Z, which consist of a simple realization


id: spherical-cow-20260505-0
file: data/en.wikipedia.org/wiki/Spherical_cow-0.md
category: reference
title: Spherical cow
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spherical_cow
date_saved: 2026-05-05T10:01:11.671992+00:00
instance: kb-cron
parent: spherical-cow-20260505-0
summary:
The spherical cow is a humorous metaphor for highly simplified scientific models of complex phenomena. Originating in theoretical physics, the metaphor refers to some scientific tendencies to develop toy models that reduce a problem to the simplest form imaginable, making calculations more feasible, even if the simplification hinders the model's application to reality. == History == The phrase comes from a joke that spoofs the simplifying assumptions sometimes used in theoretical physics. Milk production at a dairy farm was low, so the farmer wrote to the local university, asking for help from academia. A multidisciplinary team of professors was assembled, headed by a theoretical physicist, and two weeks of intensive on-site investigation took place. The scholars then returned to the university, notebooks crammed with data, where the task of writing the report was left to the team leader. Shortly thereafter the physicist returned to the farm, saying to the farmer, "I have the solution, but it works only in the case of spherical cows in a vacuum." John Harte, who received his Ph.D. from the University of Wisconsin in 1965, reported that he first heard the joke as a graduate student. One of the earliest published references is in a


id: astronomy-centre-20260505-0
file: data/en.wikipedia.org/wiki/Astronomy_Centre-0.md
category: reference
title: Astronomy Centre
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Astronomy_Centre
date_saved: 2026-05-05T10:01:13.184580+00:00
instance: kb-cron
parent: astronomy-centre-20260505-0
summary:
The Astronomy Centre, also known as the Amateur Astronomy Centre, is an astronomical observatory located in northern England which is run by experienced amateur astronomers and is open to the public at certain times. == History and purpose == Founded in November 1982 by Peter Drew, Linda Simonian and Rob Miller on the site of a disused factory, high in the Pennines, the Centre provides opportunities for its members, schools, local community groups and the general public to observe and photograph astronomical phenomena at a range of wavelengths during daylight and night hours. At the time the Centre was conceived, access to equipment and expertise was unavailable for many amateur astronomers in the UK and a national centre would have provided an invaluable focal point. Developments in optical fabrication, photography and communications now permit many visitors and members to complement their home astronomical facilities, skills and experience with those of the Astronomy Centre. In keeping with the Centres original ethos, besides welcoming visitors to the facility, current members engage off-site with schools, youth organisations and community groups and also provide contributions to national, regional, local print and broadcast media. == Structures == The first permanent housing on the site was


id: balance-of-angular-momentum-20260505-0
file: data/en.wikipedia.org/wiki/Balance_of_angular_momentum-0.md
category: reference
title: Balance of angular momentum
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Balance_of_angular_momentum
date_saved: 2026-05-05T10:01:14.393868+00:00
instance: kb-cron
parent: balance-of-angular-momentum-20260505-0
summary:
In classical mechanics, the balance of angular momentum, also known as Euler's second law, is a fundamental law of physics stating that a torque (a twisting force that causes rotation) must be applied to change the angular momentum (a measure of rotational motion) of a body. This principle, distinct from Newton's laws of motion, governs rotational dynamics. For example, to spin a playground merry-go-round, a push is needed to increase its angular momentum, while friction in the bearings and drag create opposing forces that slowly reduce it, eventually stopping the motion. First articulated by Swiss mathematician and physicist Leonhard Euler in 1775, the balance of angular momentum is a cornerstone of physics with broad applications. It implies the equality of corresponding shear stresses and the symmetry of the Cauchy stress tensor in continuum mechanics, a result also consistent with the Boltzmann Axiom, which posits that internal forces in a continuum are torque-free. These concepts—the balance of angular momentum, the symmetry of the Cauchy stress tensor, and the Boltzmann Axiom—are interconnected, as the former provides a physical basis for the latter two in continuum mechanics. It is also vital for analyzing systems like the spinning top, determining the skew-symmetric part of


id: balance-of-angular-momentum-20260505-1
file: data/en.wikipedia.org/wiki/Balance_of_angular_momentum-1.md
category: reference
title: Balance of angular momentum
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Balance_of_angular_momentum
date_saved: 2026-05-05T10:01:14.393868+00:00
instance: kb-cron
parent: balance-of-angular-momentum-20260505-0
summary:
must hold. This is actually the statement of the equality of corresponding shear stresses in the xy plane. == Cosserat Continuum == In addition to the torque-free classical continuum with a symmetric stress tensor, cosserat continua (polar continua) that are not torque-free have also been defined. One application of such a continuum is the theory of shells. Cosserat continua are not only capable to transport a momentum flux but also an angular momentum flux. Therefore, there also may be sources of momentum and angular momentum inside the body. Here the Boltzmann Axiom does not apply and the stress tensor may be skew-symmetric. If these fluxes are treated as usual in continuum mechanics, field equations arise in which the skew-symmetric part of the stress tensor has no energetic significance. The balance of angular momentum becomes independent of the balance of energy and is used to determine the skew-symmetric part of the stress tensor. American mathematician Clifford Truesdell saw in this the "true basic sense of Euler's second law". == Area rule == The area rule is a corollary of the angular momentum law in the form: The resulting moment is equal to the product of twice the mass and the time


id: euler-s-laws-of-motion-20260505-0
file: data/en.wikipedia.org/wiki/Euler's_laws_of_motion-0.md
category: reference
title: Euler's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Euler's_laws_of_motion
date_saved: 2026-05-05T10:01:15.563165+00:00
instance: kb-cron
parent: euler-s-laws-of-motion-20260505-0
summary:
In classical mechanics, Euler's laws of motion are equations of motion which extend Newton's laws of motion for point particle to rigid body motion. They were formulated by Leonhard Euler about 50 years after Isaac Newton formulated his laws. == Overview == === Euler's first law === Euler's first law states that the rate of change of linear momentum p of a rigid body is equal to the resultant of all the external forces Fext acting on the body: F ext = d p d t . {\displaystyle \mathbf {F} _{\text{ext}}={\frac {d\mathbf {p} }{dt}}.} Internal forces between the particles that make up a body do not contribute to changing the momentum of the body as there is an equal and opposite force resulting in no net effect. The linear momentum of a rigid body is the product of the mass of the body and the velocity of its center of mass vcm. === Euler's second law === Euler's second law states that the rate of change of angular momentum L about a point that is fixed in an inertial reference frame (often the center of mass of the body), is equal to the sum of the external moments of force


id: first-observation-of-gravitational-waves-20260505-0
file: data/en.wikipedia.org/wiki/First_observation_of_gravitational_waves-0.md
category: reference
title: First observation of gravitational waves
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves
date_saved: 2026-05-05T10:01:16.701964+00:00
instance: kb-cron
parent: first-observation-of-gravitational-waves-20260505-0
summary:
The first direct observation of gravitational waves was made on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016. Previously, gravitational waves had been inferred only indirectly, via their effect on the timing of pulsars in binary star systems. The waveform, detected by both LIGO observatories, matched the predictions of general relativity for a gravitational wave emanating from the inward spiral and merger of two black holes (of 36 M☉ and 29 M☉) and the subsequent ringdown of a single, 62 M☉ black hole remnant. The signal was named GW150914 (from gravitational wave and the date of observation 2015-09-14). It was also the first observation of a binary black hole merger, demonstrating both the existence of binary stellar-mass black hole systems and the fact that such mergers could occur within the current age of the universe. This first direct observation was reported around the world as a remarkable accomplishment for many reasons. Efforts to directly prove the existence of such waves had been ongoing for over fifty years, and the waves are so minuscule that Albert Einstein himself doubted that they could ever be detected. The waves given off by the cataclysmic merger


id: first-observation-of-gravitational-waves-20260505-1
file: data/en.wikipedia.org/wiki/First_observation_of_gravitational_waves-1.md
category: reference
title: First observation of gravitational waves
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves
date_saved: 2026-05-05T10:01:16.701964+00:00
instance: kb-cron
parent: first-observation-of-gravitational-waves-20260505-0
summary:
Direct observation of gravitational waves was not possible for many decades following their prediction, due to the minuscule effect that would need to be detected and separated from the background of vibrations present everywhere on Earth. A technique called interferometry was suggested in the 1960s and eventually technology developed sufficiently for this technique to become feasible. In the present approach used by LIGO, a laser beam is split and the two halves are recombined after traveling different paths. Changes to the length of the paths or the time taken for the two split beams, caused by the effect of passing gravitational waves, to reach the point where they recombine are revealed as "beats". Such a technique is extremely sensitive to tiny changes in the distance or time taken to traverse the two paths. In theory, an interferometer with arms about 4 km long would be capable of revealing the change of space-time – a tiny fraction of the size of a single proton – as a gravitational wave of sufficient strength passed through Earth from elsewhere. This effect would be perceptible only to other interferometers of a similar size, such as the Virgo, GEO 600 and planned KAGRA and INDIGO


id: first-observation-of-gravitational-waves-20260505-2
file: data/en.wikipedia.org/wiki/First_observation_of_gravitational_waves-2.md
category: reference
title: First observation of gravitational waves
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves
date_saved: 2026-05-05T10:01:16.701964+00:00
instance: kb-cron
parent: first-observation-of-gravitational-waves-20260505-0
summary:
The event happened at a luminosity distance of 440+160−180 megaparsecs (determined by the amplitude of the signal), or 1.4±0.6 billion light years, corresponding to a cosmological redshift of 0.093+0.030−0.036 (90% credible intervals). Analysis of the signal along with the inferred redshift suggested that it was produced by the merger of two black holes with masses of 35+5−3 times and 30+3−4 times the mass of the Sun (in the source frame), resulting in a post-merger black hole of 62+4−3 M☉. The mass–energy of the missing 3.0±0.5 M☉ was radiated away in the form of gravitational waves. During the final 20 milliseconds of the merger, the power of the radiated gravitational waves peaked at about 3.6×1049 watts or 526 dBm – 50 times greater than the combined power of all light radiated by all the stars in the observable universe. The amount of this energy that was received by the entire planet Earth was about 36 billion joules, of which only a small amount was absorbed. Across the 0.2-second duration of the detectable signal, the relative tangential (orbiting) velocity of the black holes increased from 30% to 60% of the speed of light. The orbital frequency of 75 Hz (half the gravitational


id: first-observation-of-gravitational-waves-20260505-3
file: data/en.wikipedia.org/wiki/First_observation_of_gravitational_waves-3.md
category: reference
title: First observation of gravitational waves
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves
date_saved: 2026-05-05T10:01:16.701964+00:00
instance: kb-cron
parent: first-observation-of-gravitational-waves-20260505-0
summary:
=== Coincident gamma-ray observation === The Fermi Gamma-ray Space Telescope reported that its Gamma-Ray Burst Monitor (GBM) instrument detected a weak gamma-ray burst above 50 keV, starting 0.4 seconds after the LIGO event and with a positional uncertainty region overlapping that of the LIGO observation. The Fermi team calculated the odds of such an event being the result of a coincidence or noise at 0.22%. However a gamma ray burst would not have been expected, and observations from the INTEGRAL telescope's all-sky SPI-ACS instrument indicated that any energy emission in gamma-rays and hard X-rays from the event was less than one millionth of the energy emitted as gravitational waves, which "excludes the possibility that the event is associated with substantial gamma-ray radiation, directed towards the observer". If the signal observed by the Fermi GBM was genuinely astrophysical, INTEGRAL would have indicated a clear detection at a significance of 15 sigma above background radiation. The AGILE space telescope also did not detect a gamma-ray counterpart of the event. A follow-up analysis by an independent group, released in June 2016, developed a different statistical approach to estimate the spectrum of the gamma-ray transient. It concluded that Fermi GBM's data did not show


id: first-observation-of-gravitational-waves-20260505-4
file: data/en.wikipedia.org/wiki/First_observation_of_gravitational_waves-4.md
category: reference
title: First observation of gravitational waves
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves
date_saved: 2026-05-05T10:01:16.701964+00:00
instance: kb-cron
parent: first-observation-of-gravitational-waves-20260505-0
summary:
=== Expectations for detection of future binary merger events === On 15 June 2016, the LIGO group announced an observation of another gravitational wave signal, named GW151226. The Advanced LIGO was predicted to detect five more black hole mergers like GW150914 in its next observing campaign from November 2016 until August 2017 (it turned out to be seven), and then 40 binary star mergers each year, in addition to an unknown number of more exotic gravitational wave sources, some of which may not be anticipated by current theory. Planned upgrades are expected to double the signal-to-noise ratio, expanding the volume of space in which events like GW150914 can be detected by a factor of ten. Additionally, Advanced Virgo, KAGRA, and a possible third LIGO detector in India will extend the network and significantly improve the position reconstruction and parameter estimation of sources. Laser Interferometer Space Antenna (LISA) is a proposed space based observation mission to detect gravitational waves. With the proposed sensitivity range of LISA, merging binaries like GW150914 would be detectable about 1000 years before they merge, providing for a class of previously unknown sources for this observatory if they exist within about 10 megaparsecs. LISA Pathfinder, LISA's technology


id: first-observation-of-gravitational-waves-20260505-5
file: data/en.wikipedia.org/wiki/First_observation_of_gravitational_waves-5.md
category: reference
title: First observation of gravitational waves
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves
date_saved: 2026-05-05T10:01:16.701964+00:00
instance: kb-cron
parent: first-observation-of-gravitational-waves-20260505-0
summary:
=== Speed of gravitational waves and limit on possible mass of graviton === The speed of gravitational waves (vg) is predicted by general relativity to be the speed of light (c). The extent of any deviation from this relationship can be parameterized in terms of the mass of the hypothetical graviton. The graviton is the name given to an elementary particle that would act as the force carrier for gravity, in quantum theories about gravity. It is expected to be massless if, as it appears, gravitation has an infinite range. (This is because the more massive a gauge boson is, the shorter is the range of the associated force; as with the infinite range of electromagnetism, which is due to the massless photon, the infinite range of gravity implies that any associated force-carrying particle would also be massless.) If the graviton were not massless, gravitational waves would propagate below lightspeed, with lower frequencies (ƒ) being slower than higher frequencies, leading to dispersion of the waves from the merger event. No such dispersion was observed. The observations of the inspiral slightly improve (lower) the upper limit on the mass of the graviton from Solar System observations to 2.1×10−58 kg, corresponding to


id: global-horizontal-sounding-technique-20260505-0
file: data/en.wikipedia.org/wiki/Global_horizontal_sounding_technique-0.md
category: reference
title: Global horizontal sounding technique
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_horizontal_sounding_technique
date_saved: 2026-05-05T10:01:17.862849+00:00
instance: kb-cron
parent: global-horizontal-sounding-technique-20260505-0
summary:
The global horizontal sounding technique (GHOST) program was an atmospheric field research project in the late 1960s for investigating the technical ability to gather weather data using hundreds of simultaneous long-duration balloons for very long-range global scale numerical weather prediction in preparation for the Global Atmospheric Research Program (GARP). == Technology == The GHOST program was to demonstrate technology for a program that would, ultimately, gather data from thousands of balloons simultaneously. Unlike radiosonde balloons which collect vertical atmospheric sounding data over the release point during a relatively short ascent lasting a few hours, horizontal sounding balloons stay aloft for much longer periods lasting several weeks or months, floating at a constant-density altitude. The GHOST design explored the performance a superpressure balloon with a spherical two-layer PET film envelope holding the gas inside at a higher pressure than the surrounding atmosphere, allowing it to maintain a nearly constant altitude. These gas balloons float at a constant density altitude, where the balloon displaces a mass of air equal to its own mass. Expansion of the lifting gas due to solar heating is avoided in a superpressure balloon, since the inextensible PET film allows the pressure to rise as the gas is


id: hulunber-grassland-ecosystem-observation-and-research-station-20260505-0
file: data/en.wikipedia.org/wiki/Hulunber_Grassland_Ecosystem_Observation_and_Research_Station-0.md
category: reference
title: Hulunber Grassland Ecosystem Observation and Research Station
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hulunber_Grassland_Ecosystem_Observation_and_Research_Station
date_saved: 2026-05-05T10:01:19.075297+00:00
instance: kb-cron
parent: hulunber-grassland-ecosystem-observation-and-research-station-20260505-0
summary:
Hulunber Grassland Ecosystem Observation and Research Station in Inner Mongolia, China, is managed by the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS). It was established in 1997 and has an area of 400ha. This station is a multi-year fenced scientific observation site for a Stipa baicalensis-dominated temperate meadow steppe. The annual precipitation is 350mm-400mm, with an average of 380mm. The annual average temperature ranges from -3°C to 1°C. The soil structure is dominated by dark chestnut soil, the soil pH is 8.3 on average, and the soil density is 1.13g/cm~3. The main species in the observation site are Stipa Baicalensis, Leymus chinensis, Filifolium sibiricum, Artemisia dracunculus, and Pulsatilla chinensis. There are 25 families and 96 genera in total. The grass coverage of this site is more than 70%, with an average height of the canopy of 50 cm and an average depth of the root of 30 cm. == References ==


id: land-lab-20260505-0
file: data/en.wikipedia.org/wiki/Land_lab-0.md
category: reference
title: Land lab
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Land_lab
date_saved: 2026-05-05T10:01:20.219358+00:00
instance: kb-cron
parent: land-lab-20260505-0
summary:
A land lab is an area of land that has been set aside for use in biological studies. Thus, it is literally an outdoor laboratory based on an area of land. Studies may be elementary or advanced. For instance, students may simply be given the task of identifying all the tree species in a land lab, or an advanced student may be doing an intensive survey of the microbial life forms found in a soil sample. Hands on, tangible, project-base learning is a key aspect of land labs within an educational context. Land labs can exist anywhere with outdoor access: educational campuses, residential neighborhoods, peri-urban settings, urban settings, or even a small courtyard. The driving principle behind land lab education is getting outside and interacting with the world directly. Land labs are often marked out in plots or transects for studies. A plot may be any size, usually marked out in square meters. This allows for more intensive, delimited studies of changes and inventories of biota. Transects are straight lines at which, at intervals, measurements are taken for a profile of the ecological community. Land labs serve an important role in giving students access to a natural environment to observe


id: land-lab-20260505-1
file: data/en.wikipedia.org/wiki/Land_lab-1.md
category: reference
title: Land lab
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Land_lab
date_saved: 2026-05-05T10:01:20.219358+00:00
instance: kb-cron
parent: land-lab-20260505-0
summary:
== Footprints and Sizes of Land Labs == Land labs can be designed in all shapes and sizes. The key attributes of a land lab are typically the following: Building an outdoor learning area designated for cross-curricular studies in a STEM environment Establishing a focus on increasing biodiversity and restoring local environmental features Educating people about meeting humans needs sustainably through agriculture, energy production, shelter, and sanitation A small land lab could be as little as a courtyard, balcony garden, or a designated patch of land outside of a classroom window. Conversely, larger land lab could encompass hundreds of acres. The ideal size for a flexible land lab space allowing for many different ecological activities and circular systems is between 1/4 of an acre to 5 acres. == Sustainable societal solutions originating from land labs == Land labs are real-life environments by design. The project-based environment encourages students, teachers, and community members to experiment with ecological solutions that can be implemented on a small scale. Ideally, the solutions and systems implemented in a land lab are transferred beyond the land lab and into the surrounding community. Composting, rainwater catchment, food-waste upcycling with methane digesters and BSF, local food production, harnessing


id: list-of-environmental-sampling-techniques-20260505-0
file: data/en.wikipedia.org/wiki/List_of_environmental_sampling_techniques-0.md
category: reference
title: List of environmental sampling techniques
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_environmental_sampling_techniques
date_saved: 2026-05-05T10:01:21.407271+00:00
instance: kb-cron
parent: list-of-environmental-sampling-techniques-20260505-0
summary:
Environmental sampling techniques are used in biology, ecology and conservation as part of scientific studies to learn about the flora and fauna of a particular area and establish a habitat's biodiversity, the abundance of species and the conditions in which these species live amongst other information. Where species are caught, researchers often then take the trapped organisms for further study in a lab or are documented by a researcher in the field before the animal is released. This information can then be used to better understand the environment, its ecology, the behaviour of species and how organisms interact with one another and their environment. Here is a list of some sampling techniques and equipment used in environmental sampling: Quadrats - used for plants and slow moving animals == Techniques for birds and/or flying invertebrates and/or bats == Malaise Trap Flight Interception Trap Harp Trap Robinson Trap Butterfly Net Mist Net == Techniques for Terrestrial Animals == Transect Tullgren Funnel - used for soil-living arthropods Pitfall Trap - used for small terrestrial animals like insects and amphibians Netting techniques for terrestrial animals Beating Net - used for insects dwelling in trees and shrubs Sweep Netting - used for insects in grasses


id: megatransect-20260505-0
file: data/en.wikipedia.org/wiki/MegaTransect-0.md
category: reference
title: MegaTransect
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/MegaTransect
date_saved: 2026-05-05T10:01:22.552842+00:00
instance: kb-cron
parent: megatransect-20260505-0
summary:
MegaTransect was the name for a project conducted in Africa in 1999 by J. Michael Fay to spend 465 days on the expedition hike of 2,000 miles (3,219 kilometers) across the Congo Basin of Africa to survey the ecological and environmental status of the region. A transect is a term in ecology that denotes a survey of the natural vegetation through a particular area. The concept of a megatransect was conceived as a vegetation transect on a large scale that could be used to take an ecological census of the natural vegetation and ecosystems. Shortly after the hike, Fay successfully lobbied alongside the President of Gabon to create 13 new national parks. In 2002, US Secretary of State Colin Powell and other Bush administration members gave 53 million dollars to help preserve the Congo Basin. Mike Fay later went on to carry out the MegaFlyover in 2004. == Madagascar megatransect == Also in 2004, an international team conducted a "Megatransect" of the island of Madagascar. Dubbed "Hike Madagascar", the journey covered the entire island. Members met with rural farmers to help them improve their agricultural techniques and discuss their impact on the environment. == History of US megatransects == One


id: newton-s-law-of-cooling-20260505-0
file: data/en.wikipedia.org/wiki/Newton's_law_of_cooling-0.md
category: reference
title: Newton's law of cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_law_of_cooling
date_saved: 2026-05-05T10:01:23.867206+00:00
instance: kb-cron
parent: newton-s-law-of-cooling-20260505-0
summary:
In the study of heat transfer, Newton's law of cooling is a physical law which states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its environment. The law is frequently qualified to include the condition that the temperature difference is small and the nature of heat transfer mechanism remains the same. As such, it is equivalent to a statement that the heat transfer coefficient, which mediates between heat losses and temperature differences, is a constant. In heat conduction, Newton's law is generally followed as a consequence of Fourier's law. The thermal conductivity of most materials is only weakly dependent on temperature, so the constant heat transfer coefficient condition is generally met. In convective heat transfer, Newton's Law is followed for forced air or pumped fluid cooling, where the properties of the fluid do not vary strongly with temperature, but it is only approximately true for buoyancy-driven convection, where the velocity of the flow increases with temperature difference. In the case of heat transfer by thermal radiation, Newton's law of cooling holds only for very small temperature differences. When stated in terms of temperature differences, Newton's law


id: newton-s-law-of-cooling-20260505-1
file: data/en.wikipedia.org/wiki/Newton's_law_of_cooling-1.md
category: reference
title: Newton's law of cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_law_of_cooling
date_saved: 2026-05-05T10:01:23.867206+00:00
instance: kb-cron
parent: newton-s-law-of-cooling-20260505-0
summary:
Δ T ( t ) = T ( t ) − T env {\displaystyle \Delta T(t)=T(t)-T_{\text{env}}} is the time-dependent temperature difference between environment and object (SI unit: K). If the heat transfer coefficient and the temperature difference are uniform along the heat transfer surface, the above formula simplifies to: Q ˙ = h A ( T ( t ) − T env ) = h A Δ T ( t ) {\displaystyle {\dot {Q}}=hA\left(T(t)-T_{\text{env}}\right)=hA\,\Delta T(t)} . The heat transfer coefficient h depends upon physical properties of the fluid and the physical situation in which convection occurs. Therefore, a single usable heat transfer coefficient (one that does not vary significantly across the temperature-difference ranges covered during cooling and heating) must be derived or found experimentally for every system that is to be analyzed. Formulas and correlations are available in many references to calculate heat transfer coefficients for typical configurations and fluids. For laminar flows, the heat transfer coefficient is usually smaller than in turbulent flows because turbulent flows have strong mixing within the boundary layer on the heat transfer surface. Note the heat transfer coefficient changes in a system when a transition from laminar to turbulent flow occurs. === Biot number


id: newton-s-law-of-cooling-20260505-2
file: data/en.wikipedia.org/wiki/Newton's_law_of_cooling-2.md
category: reference
title: Newton's law of cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_law_of_cooling
date_saved: 2026-05-05T10:01:23.867206+00:00
instance: kb-cron
parent: newton-s-law-of-cooling-20260505-0
summary:
=== First-order transient response of lumped-capacitance objects === A body treated as a lumped capacitance object, with a total internal energy of U {\displaystyle U} (in joules), is characterized by a single uniform internal temperature, T ( t ) {\displaystyle T(t)} . The heat capacitance, C {\displaystyle C} , of the body is C = d U / d T {\displaystyle C=dU/dT} (in J/K), for the case of an incompressible material. The internal energy may be written in terms of the temperature of the body, the heat capacitance (taken to be independent of temperature), and a reference temperature at which the internal energy is zero: U = C ( T − T ref ) {\displaystyle U=C(T-T_{\text{ref}})} . Differentiating U {\displaystyle U} with respect to time gives: d U d t = C d T d t . {\displaystyle {\frac {dU}{dt}}=C\,{\frac {dT}{dt}}.} Applying the first law of thermodynamics to the lumped object gives d U d t = − Q ˙ {\textstyle {\frac {dU}{dt}}=-{\dot {Q}}} , where the rate of heat transfer out of the body, Q ˙ {\displaystyle {\dot {Q}}} , may be expressed by Newton's law of cooling, and where no work transfer occurs for an incompressible material. Thus,


id: newton-s-laws-of-motion-20260505-0
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-0.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
Newton's laws of motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it. These laws, which provide the basis for Newtonian mechanics, can be paraphrased as follows: A body remains at rest, or in motion at a constant speed in a straight line, unless it is acted upon by a force. At any instant of time, the net force on a body is equal to the body's acceleration multiplied by its mass or, equivalently, the rate at which the body's momentum is changing with time. If two bodies exert forces on each other, these forces have the same magnitude but opposite directions. The three laws of motion were first stated by Isaac Newton in his Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), originally published in 1687. Newton used them to investigate and explain the motion of many physical objects and systems. In the time since Newton, new insights, especially around the concept of energy, built the field of classical mechanics on his foundations. In modern times, limitations to Newton's laws have been discovered; new theories were consequently developed, such as quantum mechanics and relativity to address the


id: newton-s-laws-of-motion-20260505-1
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-1.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
== Prerequisites == Newton's laws are often stated in terms of point or particle masses, that is, bodies whose volume is negligible. This is a reasonable approximation for real bodies when the motion of internal parts can be neglected, and when the separation between bodies is much larger than the size of each. For instance, the Earth and the Sun can both be approximated as pointlike when considering the orbit of the former around the latter, but the Earth is not pointlike when considering activities on its surface. The mathematical description of motion, or kinematics, is based on the idea of specifying positions using numerical coordinates. Movement is represented by these numbers changing over time: a body's trajectory is represented by a function that assigns to each value of a time variable the values of all the position coordinates. The simplest case is one-dimensional, that is, when a body is constrained to move only along a straight line. Its position can then be given by a single number, indicating where it is relative to some chosen reference point. For example, a body might be free to slide along a track that runs left to right, and so its location can


id: newton-s-laws-of-motion-20260505-2
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-2.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
== Laws == === First law === Every body continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. Newton's first law expresses the principle of inertia: the natural behavior of a body is to move in a straight line at constant speed. A body's motion preserves the status quo, but external forces can perturb this. The modern understanding of Newton's first law is that no inertial observer is privileged over any other. The concept of an inertial observer makes quantitative the everyday idea of feeling no effects of motion. For example, a person standing on the ground watching a train go past is an inertial observer. If the observer on the ground sees the train moving smoothly in a straight line at a constant speed, then a passenger sitting on the train will also be an inertial observer: the train passenger feels no motion. The principle expressed by Newton's first law is that there is no way to say which inertial observer is "really" moving and which is "really" standing still. One observer's state of rest is another observer's state of uniform


id: newton-s-laws-of-motion-20260505-3
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-3.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
In other words, if one body exerts a force on a second body, the second body is also exerting a force on the first body, of equal magnitude in the opposite direction. Overly brief paraphrases of the third law, like "action equals reaction" might have caused confusion among generations of students: the "action" and "reaction" apply to different bodies. For example, consider a book at rest on a table. The Earth's gravity pulls down upon the book. The "reaction" to that "action" is not the support force from the table holding up the book, but the gravitational pull of the book acting on the Earth. Newton's third law relates to a more fundamental principle, the conservation of momentum. The latter remains true even in cases where Newton's statement does not, for instance when force fields as well as material bodies carry momentum (e.g., in electromagnetism), and when momentum is defined properly, in quantum mechanics as well. In Newtonian mechanics, if two bodies have momenta p 1 {\displaystyle \mathbf {p} _{1}} and p 2 {\displaystyle \mathbf {p} _{2}} respectively, then the total momentum of the pair is p = p 1 + p 2 {\displaystyle \mathbf {p} =\mathbf {p} _{1}+\mathbf {p}


id: newton-s-laws-of-motion-20260505-4
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-4.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
When a body is in uniform circular motion, the force on it changes the direction of its motion but not its speed. For a body moving in a circle of radius r {\displaystyle r} at a constant speed v {\displaystyle v} , its acceleration has a magnitude a = v 2 r {\displaystyle a={\frac {v^{2}}{r}}} and is directed toward the center of the circle. The force required to sustain this acceleration, called the centripetal force, is therefore also directed toward the center of the circle and has magnitude m v 2 / r {\displaystyle mv^{2}/r} . Many orbits, such as that of the Moon around the Earth, can be approximated by uniform circular motion. In such cases, the centripetal force is gravity, and by Newton's law of universal gravitation has magnitude G M m / r 2 {\displaystyle GMm/r^{2}} , where M {\displaystyle M} is the mass of the larger body being orbited. Therefore, the mass of a body can be calculated from observations of another body orbiting around it. Newton's cannonball is a thought experiment that interpolates between projectile motion and uniform circular motion. A cannonball that is lobbed weakly off the edge of a tall cliff will hit


id: newton-s-laws-of-motion-20260505-5
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-5.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
The fan and sail example is a situation studied in discussions of Newton's third law. In the situation, a fan is attached to a cart or a sailboat and blows on its sail. From the third law, one would reason that the force of the air pushing in one direction would cancel out the force done by the fan on the sail, leaving the entire apparatus stationary. However, because the system is not entirely enclosed, there are conditions in which the vessel will move; for example, if the sail is built in a manner that redirects the majority of the airflow back towards the fan, the net force will result in the vessel moving forward. == Work and energy == The concept of energy was developed after Newton's time, but it has become an inseparable part of what is considered "Newtonian" physics. Energy can broadly be classified into kinetic, due to a body's motion, and potential, due to a body's position relative to others. Thermal energy, the energy carried by heat flow, is a type of kinetic energy not associated with the macroscopic motion of objects but instead with the movements of the atoms and molecules of which they are


id: newton-s-laws-of-motion-20260505-6
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-6.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
=== Rotational analogues of Newton's laws === When Newton's laws are applied to rotating extended bodies, they lead to new quantities that are analogous to those invoked in the original laws. The analogue of mass is the moment of inertia, the counterpart of momentum is angular momentum, and the counterpart of force is torque. Angular momentum is calculated with respect to a reference point. If the displacement vector from a reference point to a body is r {\displaystyle \mathbf {r} } and the body has momentum p {\displaystyle \mathbf {p} } , then the body's angular momentum with respect to that point is, using the vector cross product, L = r × p . {\displaystyle \mathbf {L} =\mathbf {r} \times \mathbf {p} .} Taking the time derivative of the angular momentum gives d L d t = ( d r d t ) × p + r × d p d t = v × m v + r × F . {\displaystyle {\frac {\mathrm {d} \mathbf {L} }{\mathrm {d} t}}=\left({\frac {\mathrm {d} \mathbf {r} }{\mathrm {d} t}}\right)\times \mathbf {p} +\mathbf {r} \times {\frac {\mathrm {d} \mathbf {p} }{\mathrm {d} t}}=\mathbf {v} \times m\mathbf {v} +\mathbf {r} \times \mathbf {F}


id: newton-s-laws-of-motion-20260505-7
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-7.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
∂ v ∂ t + ( ∇ ⋅ v ) v = − 1 ρ ∇ P + f , {\displaystyle {\frac {\partial v}{\partial t}}+(\mathbf {\nabla } \cdot \mathbf {v} )\mathbf {v} =-{\frac {1}{\rho }}\mathbf {\nabla } P+\mathbf {f} ,} where ρ {\displaystyle \rho } is the density, P {\displaystyle P} is the pressure, and f {\displaystyle \mathbf {f} } stands for an external influence like a gravitational pull. Incorporating the effect of viscosity turns the Euler equation into a Navier–Stokes equation: ∂ v ∂ t + ( ∇ ⋅ v ) v = − 1 ρ ∇ P + ν ∇ 2 v + f , {\displaystyle {\frac {\partial v}{\partial t}}+(\mathbf {\nabla } \cdot \mathbf {v} )\mathbf {v} =-{\frac {1}{\rho }}\mathbf {\nabla } P+\nu \nabla ^{2}\mathbf {v} +\mathbf {f} ,} where ν {\displaystyle \nu } is the kinematic viscosity. === Singularities === It is mathematically possible for a collection of point masses, moving in accord with Newton's laws, to launch some of themselves away so forcefully that they fly off to infinity in a finite time. This unphysical behavior, known as a "noncollision singularity", depends upon the masses being pointlike and able to approach one another arbitrarily closely, as


id: newton-s-laws-of-motion-20260505-8
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-8.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
d q d t = p m , {\displaystyle {\frac {\mathrm {d} q}{\mathrm {d} t}}={\frac {p}{m}},} which reproduces the familiar statement that a body's momentum is the product of its mass and velocity. The time derivative of the momentum is d p d t = − d V d q , {\displaystyle {\frac {\mathrm {d} p}{\mathrm {d} t}}=-{\frac {\mathrm {d} V}{\mathrm {d} q}},} which, upon identifying the negative derivative of the potential with the force, is just Newton's second law once again. As in the Lagrangian formulation, in Hamiltonian mechanics the conservation of momentum can be derived using Noether's theorem, making Newton's third law an idea that is deduced rather than assumed. Among the proposals to reform the standard introductory-physics curriculum is one that teaches the concept of energy before that of force, essentially "introductory Hamiltonian mechanics". === Hamilton–Jacobi === The Hamilton–Jacobi equation provides yet another formulation of classical mechanics, one which makes it mathematically analogous to wave optics. This formulation also uses Hamiltonian functions, but in a different way than the formulation described above. The paths taken by bodies or collections of bodies are deduced from a function S ( q 1 , q 2 , … , t


id: newton-s-laws-of-motion-20260505-9
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-9.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
=== Electromagnetism === Newton's three laws can be applied to phenomena involving electricity and magnetism, though subtleties and caveats exist. Coulomb's law for the electric force between two stationary, electrically charged bodies has much the same mathematical form as Newton's law of universal gravitation: the force is proportional to the product of the charges, inversely proportional to the square of the distance between them, and directed along the straight line between them. The Coulomb force that a charge q 1 {\displaystyle q_{1}} exerts upon a charge q 2 {\displaystyle q_{2}} is equal in magnitude to the force that q 2 {\displaystyle q_{2}} exerts upon q 1 {\displaystyle q_{1}} , and it points in the exact opposite direction. Coulomb's law is thus consistent with Newton's third law. Electromagnetism treats forces as produced by fields acting upon charges. The Lorentz force law provides an expression for the force upon a charged body that can be plugged into Newton's second law in order to calculate its acceleration. According to the Lorentz force law, a charged body in an electric field experiences a force in the direction of that field, a force proportional to its charge q {\displaystyle q} and to the strength of


id: newton-s-laws-of-motion-20260505-10
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-10.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
=== General relativity === General relativity is a theory of gravity that advances beyond that of Newton. In general relativity, the gravitational force of Newtonian mechanics is reimagined as curvature of spacetime. A curved path like an orbit, attributed to a gravitational force in Newtonian mechanics, is not the result of a force deflecting a body from an ideal straight-line path, but rather the body's attempt to fall freely through a background that is itself curved by the presence of other masses. A remark by John Archibald Wheeler that has become proverbial among physicists summarizes the theory: "Spacetime tells matter how to move; matter tells spacetime how to curve." Wheeler himself thought of this reciprocal relationship as a modern, generalized form of Newton's third law. The relation between matter distribution and spacetime curvature is given by the Einstein field equations, which require tensor calculus to express. The Newtonian theory of gravity is a good approximation to the predictions of general relativity when gravitational effects are weak and objects are moving slowly compared to the speed of light. === Quantum mechanics === Quantum mechanics is a theory of physics originally developed in order to understand microscopic phenomena: behavior at the scale


id: newton-s-laws-of-motion-20260505-11
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-11.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
Imagine any particle projected along a horizontal plane without friction; then we know, from what has been more fully explained in the preceding pages, that this particle will move along this same plane with a motion which is uniform and perpetual, provided the plane has no limits. Galileo recognized that in projectile motion, the Earth's gravity affects vertical but not horizontal motion. However, Galileo's idea of inertia was not exactly the one that would be codified into Newton's first law. Galileo thought that a body moving a long distance inertially would follow the curve of the Earth. This idea was corrected by Isaac Beeckman, Descartes, and Pierre Gassendi, who recognized that inertial motion should be motion in a straight line. Descartes published his laws of nature (laws of motion) with this correction in Principles of Philosophy (Principia Philosophiae) in 1644, with the heliocentric part toned down. First Law of Nature: Each thing when left to itself continues in the same state; so any moving body goes on moving until something stops it. Second Law of Nature: Each moving thing if left to itself moves in a straight line; so any body moving in a circle always tends to move away


id: newton-s-laws-of-motion-20260505-12
file: data/en.wikipedia.org/wiki/Newton's_laws_of_motion-12.md
category: reference
title: Newton's laws of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newton's_laws_of_motion
date_saved: 2026-05-05T10:01:25.048867+00:00
instance: kb-cron
parent: newton-s-laws-of-motion-20260505-0
summary:
Newton expressed his second law by saying that the force on a body is proportional to its change of motion, or momentum. By the time he wrote the Principia, he had already developed calculus (which he called "the science of fluxions"), but in the Principia he made no explicit use of it, perhaps because he believed geometrical arguments in the tradition of Euclid to be more rigorous. Consequently, the Principia does not express acceleration as the second derivative of position, and so it does not give the second law as F = m a {\displaystyle F=ma} . This form of the second law was written (for the special case of constant force) at least as early as 1716, by Jakob Hermann; Leonhard Euler would employ it as a basic premise in the 1740s. Euler pioneered the study of rigid bodies and established the basic theory of fluid dynamics. Pierre-Simon Laplace's five-volume Traité de mécanique céleste (1798–1825) forsook geometry and developed mechanics purely through algebraic expressions, while resolving questions that the Principia had left open, like a full theory of the tides. The concept of energy became a key part of Newtonian mechanics in the post-Newton period. Huygens' solution of the


id: observational-astronomy-20260505-0
file: data/en.wikipedia.org/wiki/Observational_astronomy-0.md
category: reference
title: Observational astronomy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observational_astronomy
date_saved: 2026-05-05T10:01:26.206992+00:00
instance: kb-cron
parent: observational-astronomy-20260505-0
summary:
Observational astronomy is a division of astronomy that is concerned with recording data about the observable universe, the practice and study of observing celestial objects with the use of telescopes and other astronomical instruments. As a science, the study of astronomy does not rely on direct experiments with the objects in a distant universe. Rather astronomers have a vast number of visible examples of stellar phenomena that can be examined. This allows for observational data to be plotted on graphs, and general trends recorded. Nearby examples of specific phenomena, such as variable stars, can then be used to infer the behavior of more distant representatives. Those distant yardsticks can then be employed to measure other phenomena in that neighborhood, including the distance to a galaxy. Galileo Galilei turned a telescope to the heavens and recorded what he saw. Since that time, observational astronomy has made steady advances with each improvement in telescope technology. == Subdivisions == A traditional division of observational astronomy is based on the region of the electromagnetic spectrum observed: Radio astronomy detects radiation of millimetre to decametre wavelength. The receivers are similar to those used in radio broadcast transmission but much more sensitive. See also Radio telescopes.


id: observational-astronomy-20260505-1
file: data/en.wikipedia.org/wiki/Observational_astronomy-1.md
category: reference
title: Observational astronomy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observational_astronomy
date_saved: 2026-05-05T10:01:26.206992+00:00
instance: kb-cron
parent: observational-astronomy-20260505-0
summary:
=== Measuring results === Astronomers have a number of observational tools that they can use to make measurements of the heavens. For objects that are relatively close to the Sun and Earth, direct and very precise position measurements can be made against a more distant (and thereby nearly stationary) background. Early observations of this nature were used to develop very precise orbital models of the various planets, and to determine their respective masses and gravitational perturbations. Such measurements led to the discovery of the planets Uranus, Neptune, and (indirectly) Pluto. They also resulted in an erroneous assumption of a fictional planet Vulcan within the orbit of Mercury (but the explanation of the precession of Mercury's orbit by Einstein is considered one of the triumphs of his general relativity theory). == Developments and diversity == In addition to examination of the universe in the optical spectrum, astronomers have increasingly been able to acquire information in other portions of the electromagnetic spectrum. The earliest such non-optical measurements were made of the thermal properties of the Sun. Instruments employed during a solar eclipse could be used to measure the radiation from the corona. === Radio astronomy === With the discovery of radio waves,


id: observational-astronomy-20260505-2
file: data/en.wikipedia.org/wiki/Observational_astronomy-2.md
category: reference
title: Observational astronomy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observational_astronomy
date_saved: 2026-05-05T10:01:26.206992+00:00
instance: kb-cron
parent: observational-astronomy-20260505-0
summary:
The key instrument of nearly all modern observational astronomy is the telescope. This serves the dual purposes of gathering more light so that very faint objects can be observed, and magnifying the image so that small and distant objects can be observed. Optical astronomy requires telescopes that use optical components of great precision. Typical requirements for grinding and polishing a curved mirror, for example, require the surface to be within a fraction of a wavelength of light of a particular conic shape. Many modern "telescopes" actually consist of arrays of telescopes working together to provide higher resolution through aperture synthesis. Large telescopes are housed in domes, both to protect them from the weather and to stabilize the environmental conditions. For example, if the temperature is different from one side of the telescope to the other, the shape of the structure changes, due to thermal expansion pushing optical elements out of position. This can affect the image. For this reason, the domes are usually bright white (titanium dioxide) or unpainted metal. Domes are often opened around sunset, long before observing can begin, so that air can circulate and bring the entire telescope to the same temperature as the surroundings. To prevent


id: observational-astronomy-20260505-3
file: data/en.wikipedia.org/wiki/Observational_astronomy-3.md
category: reference
title: Observational astronomy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observational_astronomy
date_saved: 2026-05-05T10:01:26.206992+00:00
instance: kb-cron
parent: observational-astronomy-20260505-0
summary:
=== Photoelectric photometry === Photoelectric photometry using the CCD is now frequently used to make observations through a telescope. These sensitive instruments can record the image nearly down to the level of individual photons, and can be designed to view in parts of the spectrum that are invisible to the eye. The ability to record the arrival of small numbers of photons over a period of time can allow a degree of computer correction for atmospheric effects, sharpening up the image. Multiple digital images can also be combined to further enhance the image, often known as "stacking". When combined with the adaptive optics technology, image quality can approach the theoretical resolution capability of the telescope. Filters are used to view an object at particular frequencies or frequency ranges. Multilayer film filters can provide very precise control of the frequencies transmitted and blocked, so that, for example, objects can be viewed at a particular frequency emitted only by excited hydrogen atoms. Filters can also be used to partially compensate for the effects of light pollution by blocking out unwanted light. Polarization filters can also be used to determine if a source is emitting polarized light, and the orientation of the polarization.


id: observatory-20260505-0
file: data/en.wikipedia.org/wiki/Observatory-0.md
category: reference
title: Observatory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observatory
date_saved: 2026-05-05T10:01:27.492417+00:00
instance: kb-cron
parent: observatory-20260505-0
summary:
An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. The term observatoire has been used in French since at least 1976 to denote any institution that compiles and presents data on a particular subject (such as public health observatory) or for a particular geographic area (European Audiovisual Observatory). == Astronomical observatories == Astronomical observatories are mainly divided into four categories according to location: space-based, airborne, ground-based, and underground-based. Historically, ground-based observatories were as simple as containing a mural instrument (for measuring the angle between stars) or Stonehenge (which has some alignments on astronomical phenomena). Astronomical observatories may be private or they may be public. === Ground-based observatories === Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases,


id: observatory-20260505-1
file: data/en.wikipedia.org/wiki/Observatory-1.md
category: reference
title: Observatory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observatory
date_saved: 2026-05-05T10:01:27.492417+00:00
instance: kb-cron
parent: observatory-20260505-0
summary:
825: Al-Shammisiyyah Observatory, Baghdad, Iraq 869: Mahodayapuram Observatory, Kerala, India 1259: Maragheh Observatory, Azerbaijan, Iran 1276: Gaocheng Astronomical Observatory, China 1420: Ulugh Beg Observatory, Samarqand, Uzbekistan 1442: Beijing Ancient Observatory, China 1577: Constantinople Observatory of Taqi ad-Din, Turkey 1580: Uraniborg, Denmark (present-day Sweden) 1581: Stjärneborg, Denmark (present-day Sweden) 1633: Leiden Observatory, Netherlands 1642: Panzano Observatory, Italy 1642: Round Tower, Denmark 1667: Paris Observatory, France 1675: Royal Greenwich Observatory, England 1695: Sukharev Tower, Russia 1711: Berlin Observatory, Germany 1724: Jantar Mantar, India 1753: Stockholm Observatory, Sweden 1753: Vilnius University Observatory, Lithuania 1753: Real Instituto y Observatorio de la Armada, Spain 1759: Trieste Observatory, Italy. 1757: Macfarlane Observatory, Scotland. 1759: Turin Observatory, Italy. 1764: Brera Astronomical Observatory, Italy. 1765: Mohr Observatory, Indonesia. 1771: Lviv Observatory, Ukraine. 1774: Observatory of the Vatican, Italy. 1785: Dunsink Observatory, Ireland. 1786: Madras Observatory, India. 1789: Armagh Observatory, Northern Ireland. 1790: Royal Observatory of Madrid, Spain, 1803: National Astronomical Observatory, Bogotá, Colombia. 1811: Tartu Old Observatory, Estonia 1812: Astronomical Observatory of Capodimonte, Naples, Italy 1830/1842: Depot of Charts & Instruments/US Naval Observatory, US 1830: Yale University Observatory Atheneum, US 1834: Helsinki University Observatory, Finland 1838: Hopkins Observatory, Williams College, US 1838: Loomis Observatory, Western Reserve Academy, US


id: observatory-20260505-2
file: data/en.wikipedia.org/wiki/Observatory-2.md
category: reference
title: Observatory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Observatory
date_saved: 2026-05-05T10:01:27.492417+00:00
instance: kb-cron
parent: observatory-20260505-0
summary:
A volcano observatory is an institution that conducts the monitoring of a volcano as well as research in order to understand the potential impacts of active volcanism. Among the best known are the Hawaiian Volcano Observatory and the Vesuvius Observatory. Mobile volcano observatories exist with the USGS VDAP (Volcano Disaster Assistance Program), to be deployed on demand. Each volcano observatory has a geographic area of responsibility it is assigned to whereby the observatory is tasked with spreading activity forecasts, analyzing potential volcanic activity threats and cooperating with communities in preparation for volcanic eruption. == See also == == References == == Further reading == Aubin, David; Charlotte Bigg, and H. Otto Sibum, eds. The Heavens on Earth: Observatories and Astronomy in Nineteenth-Century Science and Culture (Duke University Press; 2010) 384 pages; Topics include astronomy as military science in Sweden, the Pulkovo Observatory in the Russia of Czar Nicholas I, and physics and the astronomical community in late 19th-century America. Brunier, Serge, et al. Great Observatories of the World (2005). Dick, Steven. Sky and Ocean Joined: The U.S. Naval Observatory 1830–2000 (2003). Gressot Julien and Jeanneret Romain, « Determining the right time, or the establishment of a culture of astronomical precision


id: operation-moonwatch-20260505-0
file: data/en.wikipedia.org/wiki/Operation_Moonwatch-0.md
category: reference
title: Operation Moonwatch
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Operation_Moonwatch
date_saved: 2026-05-05T10:01:28.689584+00:00
instance: kb-cron
parent: operation-moonwatch-20260505-0
summary:
Operation Moonwatch (also known as Project Moonwatch and, more simply, as Moonwatch) was an amateur science program formally initiated by the Smithsonian Astrophysical Observatory (SAO) in 1956. The SAO organized Moonwatch as part of the International Geophysical Year (IGY). Its initial goal was to enlist the aid of amateur astronomers and other citizens who would help professional scientists spot the first artificial satellites. Until professionally staffed optical tracking stations came on-line in 1958, this network of amateur scientists and other interested citizens played a critical role in providing crucial information regarding the world's first satellites. == Origins of Moonwatch == Moonwatch's origins can be traced to two sources. In the United States, there was a thriving culture of amateur scientists including thousands of citizens who did astronomy for an avocation. During the Cold War, the United States also encouraged thousands of citizens to take part in the Ground Observer Corps, a nationwide program to spot Soviet bombers. Moonwatch brought together these two activities and attitudes, melding curiosity and vigilance into a thriving activity for citizens. Moonwatch, in other words, was an expression of 1950s popular culture and fixed properly within the context of the Cold War. Moonwatch was the brainchild


id: operation-moonwatch-20260505-1
file: data/en.wikipedia.org/wiki/Operation_Moonwatch-1.md
category: reference
title: Operation Moonwatch
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Operation_Moonwatch
date_saved: 2026-05-05T10:01:28.689584+00:00
instance: kb-cron
parent: operation-moonwatch-20260505-0
summary:
Sputnik 1's sudden launch was followed less than a month later with the Soviets orbiting Sputnik 2 and the dog Laika. It was Moonwatch teams, networked around the world, who provided tracking information needed by scientists in Western nations. For the opening months of the Space Age, members of Moonwatch were the only organized worldwide network that was prepared to spot and help track satellites. The information they provided was complemented by the radio tracking program called Minitrack the United States Navy operated as well as some information from amateur radio buffs. In many cases, Moonwatch teams also had the responsibility of communicating news of Sputnik and the first American satellites to the public. The public responded, in turn, with infectious enthusiasm as local radio stations aired times to spot satellites and local and national newspapers ran hundreds of articles that described the nighttime activities of Moonwatchers. Moonwatch caught the attention of those citizens interested in science or the Space Race during the late 1950s and much of the general public as well. Newspapers and popular magazines featured stories about Moonwatch regularly; dozens of articles appeared in the Los Angeles Times, The New Yorker, and the New York Times alone.


id: streetlight-effect-20260505-0
file: data/en.wikipedia.org/wiki/Streetlight_effect-0.md
category: reference
title: Streetlight effect
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Streetlight_effect
date_saved: 2026-05-05T10:01:29.854458+00:00
instance: kb-cron
parent: streetlight-effect-20260505-0
summary:
The streetlight effect, or the drunkard's search principle, is a type of observational bias that occurs when people only search for something where it is easiest to look. Both names refer to a well-known joke: A policeman sees a drunk man searching for something under a streetlight and asks what the drunk has lost. He says he lost his keys and they both look under the streetlight together. After a few minutes the policeman asks if he is sure he lost them here, and the drunk replies, no, and that he lost them in the park. The policeman asks why he is searching here, and the drunk replies, "this is where the light is". The anecdote appears in a story of the Islamic folklore character Nasreddin. In an undated Persian version of the story, Nasreddin loses a ring in a dark room of his house but instead looks for it in the yard because there is "much more light" out there. According to Idries Shah, this tale is used by many Sufis, commenting upon people who seek exotic sources for enlightenment. The version with a drunk under a streetlight goes back at least to the 1920s, and has been used


id: transect-20260505-0
file: data/en.wikipedia.org/wiki/Transect-0.md
category: reference
title: Transect
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Transect
date_saved: 2026-05-05T10:01:31.001886+00:00
instance: kb-cron
parent: transect-20260505-0
summary:
A transect is a path along which one counts and records occurrences of the objects of study (e.g. plants). It requires an observer to move along a fixed path and to count occurrences along the path and, at the same time (in some procedures), obtain the distance of the object from the path. This results in an estimate of the area covered and an estimate of the way in which detectability increases from probability 0 (far from the path) towards 1 (near the path). Using the raw count and this probability function, one can arrive at an estimate of the actual density of objects. The estimation of the abundance of populations (such as terrestrial mammal species) can be achieved using a number of different types of transect methods, such as strip transects, line transects, belt transects, point transects, gradsects and curved line transects. == See also == Census – Compilation of information about a given population Mark and recapture – Animal population estimation method – Method for estimating a species population size Distance sampling – Methods for estimating the density and/or abundance of populations MegaTransect – 1999 ecological survey of Africa == References == == External links == The dictionary


id: weather-balloon-20260505-0
file: data/en.wikipedia.org/wiki/Weather_balloon-0.md
category: reference
title: Weather balloon
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Weather_balloon
date_saved: 2026-05-05T10:01:32.254307+00:00
instance: kb-cron
parent: weather-balloon-20260505-0
summary:
A weather balloon, also known as a sounding balloon, is a high-altitude balloon (HAB) that carries instruments into the stratosphere for measuring atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde. First invented in the late 19th century, weather balloons have overgone several remodels and are still used by researchers across Europe, North America, and Asia to this day. The balloon itself is made of latex and filled with either helium or hydrogen to produce lift. Balloons can be tracked by radar, RDF, or GPS. Balloons meant to stay at a constant altitude for long periods are known as transosondes. Weather balloons that do not carry an instrument pack are used to determine upper-level winds and the height of cloud layers. For such balloons, a theodolite or total station is used to track the balloon's azimuth and elevation, which are then converted to estimated wind speed and direction and/or cloud height, as applicable. Weather balloons are launched around the world for observations used to diagnose current conditions as well as by human forecasters and computer models for weather forecasting. Between 900 and 1,300 locations around the globe do routine releases, typically


id: weather-balloon-20260505-1
file: data/en.wikipedia.org/wiki/Weather_balloon-1.md
category: reference
title: Weather balloon
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Weather_balloon
date_saved: 2026-05-05T10:01:32.254307+00:00
instance: kb-cron
parent: weather-balloon-20260505-0
summary:
=== Aerospace and rocket launch support === Weather balloons are also used as atmospheric sounding systems to assist with rocket launches. In a test performed by the Lukasiewicz Research Network - Institute of Aviation a balloon sounding system was used to assist the ILR-33 Amber sub-orbital rocket. In a series of test launches in 2019, the system acquired atmospheric data such as information on vertical wind profile in real time that was used in pre-launch procedures for the rocket. === Special uses === Specialized uses also exist, such as for aviation interests, pollution monitoring, photography or videography, and research. Examples include pilot balloons (Pibal). Field research programs often use mobile launchers from land vehicles as well as ships and aircraft (usually dropsondes in this case). In recent years, weather balloons have also been used for scattering human ashes at high altitudes. The weather balloon was also used to create the fictional entity 'Rover' during the production of the 1960s TV series The Prisoner in Portmeirion, Gwynedd, North Wales, UK in September 1966. This was retained in further scenes shot at MGM Borehamwood UK during 1966–67. Weather balloons have also been adapted as drifting platforms in chemistry and air quality research.


id: analysis-20260505-0
file: data/en.wikipedia.org/wiki/Analysis-0.md
category: reference
title: Analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Analysis
date_saved: 2026-05-05T10:01:33.841259+00:00
instance: kb-cron
parent: analysis-20260505-0
summary:
Analysis (pl.: analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle, though analysis as a formal concept is a relatively recent development. The word comes from the Ancient Greek ἀνάλυσις (analysis, "a breaking-up" or "an untying" from ana- "up, throughout" and lysis "a loosening"). From it also comes the word's plural, analyses. As a formal concept, the method has variously been ascribed to René Descartes (Discourse on the Method), and Galileo Galilei. It has also been ascribed to Isaac Newton, in the form of a practical method of physical discovery (which he did not name). The converse of analysis is synthesis: putting the pieces back together again in a new or different whole. == Academic analysis == Academic analysis is a systematic, methodological approach to inquiry used across scholarly disciplines to deconstruct complex ideas, texts, data, or systems. Its primary aim is to foster a deeper, evidence-based understanding, challenge assumptions, and contribute to a body of knowledge through critical examination and rigorous argumentation. This form of analysis is foundational to higher


id: analysis-20260505-1
file: data/en.wikipedia.org/wiki/Analysis-1.md
category: reference
title: Analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Analysis
date_saved: 2026-05-05T10:01:33.841259+00:00
instance: kb-cron
parent: analysis-20260505-0
summary:
=== Music === Musical analysis – a process attempting to answer the question "How does this music work?" Musical Analysis is a study of how the composers use the notes together to compose music. Those studying music will find differences with each composer's musical analysis, which differs depending on the culture and history of music studied. An analysis of music is meant to simplify the music for you. Schenkerian analysis Schenkerian analysis is a collection of music analysis that focuses on the production of the graphic representation. This includes both analytical procedure as well as the notational style. Simply put, it analyzes tonal music which includes all chords and tones within a composition. === Philosophy === Philosophical analysis – a general term for the techniques used by philosophers Philosophical analysis refers to the clarification and composition of words put together and the entailed meaning behind them. Philosophical analysis dives deeper into the meaning of words and seeks to clarify that meaning by contrasting the various definitions. It is the study of reality, justification of claims, and the analysis of various concepts. Branches of philosophy include logic, justification, metaphysics, values and ethics. If questions can be answered empirically, meaning it can


id: analysis-20260505-2
file: data/en.wikipedia.org/wiki/Analysis-2.md
category: reference
title: Analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Analysis
date_saved: 2026-05-05T10:01:33.841259+00:00
instance: kb-cron
parent: analysis-20260505-0
summary:
The synthetic proof proceeds by shewing that the proposed new truth involves certain admitted truths. An analytic proof begins by an assumption, upon which a synthetic reasoning is founded. The Greeks distinguished theoretic from problematic analysis. A theoretic analysis is of the following kind. To prove that A is B, assume first that A is B. If so, then, since B is C and C is D and D is E, therefore A is E. If this be known a falsity, A is not B. But if this be a known truth and all the intermediate propositions be convertible, then the reverse process, A is E, E is D, D is C, C is B, therefore A is B, constitutes a synthetic proof of the original theorem. Problematic analysis is applied in all cases where it is proposed to construct a figure which is assumed to satisfy a given condition. The problem is then converted into some theorem which is involved in the condition and which is proved synthetically, and the steps of this synthetic proof taken backwards are a synthetic solution of the problem. === Psychotherapy === Psychoanalysis – seeks to elucidate connections among unconscious components of patients' mental


id: animal-testing-20260505-0
file: data/en.wikipedia.org/wiki/Animal_testing-0.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals, as model organisms, in experiments that seek answers to scientific and medical questions. This approach can be contrasted with field studies in which animals are observed in their natural environments or habitats. Experimental research with animals is usually conducted in universities, medical schools, pharmaceutical companies, defense establishments, and commercial facilities that provide animal-testing services to the industry. The focus of animal testing varies on a continuum from pure research, focusing on developing fundamental knowledge of an organism, to applied research, which may focus on answering some questions of great practical importance, such as finding a cure for a disease. Examples of applied research include testing disease treatments, breeding, defense research, and toxicology, including cosmetics testing. In education, animal testing is sometimes a component of biology or psychology courses. Research using animal models has been central to most of the achievements of modern medicine. It has contributed to most of the basic knowledge in fields such as human physiology and biochemistry, and has played significant roles in fields such as neuroscience and infectious disease. The results have included the near-eradication of polio


id: animal-testing-20260505-1
file: data/en.wikipedia.org/wiki/Animal_testing-1.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
The earliest references to animal testing are found in the writings of the Greeks in the 2nd and 4th centuries BCE. Aristotle and Erasistratus were among the first to perform experiments on living animals. Galen, a 2nd-century Roman physician, performed post-mortem dissections of pigs and goats. Avenzoar, a 12th-century Arabic physician in Moorish Spain introduced an experimental method of testing surgical procedures before applying them to human patients. Discoveries in the 18th and 19th centuries included Antoine Lavoisier's use of a guinea pig in a calorimeter to prove that respiration was a form of combustion, and Louis Pasteur's demonstration of the germ theory of disease in the 1880s using anthrax in sheep. Robert Koch used animal testing of mice and guinea pigs to discover the bacteria that cause anthrax and tuberculosis. In the 1890s, Ivan Pavlov famously used dogs to describe classical conditioning. Research using animal models has been central to most of the achievements of modern medicine. It has contributed most of the basic knowledge in fields such as human physiology and biochemistry, and has played significant roles in fields such as neuroscience and infectious disease. For example, the results have included the near-eradication of polio and the development


id: animal-testing-20260505-2
file: data/en.wikipedia.org/wiki/Animal_testing-2.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
== Model organisms == === Invertebrates === Although many more invertebrates than vertebrates are used in animal testing, these studies are largely unregulated by law. The most frequently used invertebrate species are Drosophila melanogaster, a fruit fly, and Caenorhabditis elegans, a nematode worm. In the case of C. elegans, the worm's body is completely transparent and the precise lineage of all the organism's cells is known, while studies in the fly D. melanogaster can use an amazing array of genetic tools. These invertebrates offer some advantages over vertebrates in animal testing, including their short life cycle and the ease with which large numbers may be housed and studied. However, the lack of an adaptive immune system and their simple organs prevent worms from being used in several aspects of medical research such as vaccine development. Similarly, the fruit fly immune system differs greatly from that of humans, and diseases in insects can be different from diseases in vertebrates; however, fruit flies and waxworms can be useful in studies to identify novel virulence factors or pharmacologically active compounds. Several invertebrate systems are considered acceptable alternatives to vertebrates in early-stage discovery screens. Because of similarities between the innate immune system of insects


id: animal-testing-20260505-3
file: data/en.wikipedia.org/wiki/Animal_testing-3.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
Non-human primates (NHPs) are used in toxicology tests, studies of AIDS and hepatitis, studies of neurology, behavior and cognition, reproduction, genetics, and xenotransplantation. They are caught in the wild or purpose-bred. In the United States and China, most primates are domestically purpose-bred, whereas in Europe the majority are imported purpose-bred. The European Commission reported that in 2011, 6,012 monkeys were experimented on in European laboratories. According to the U.S. Department of Agriculture, there were 71,188 monkeys in U.S. laboratories in 2016. 23,465 monkeys were imported into the U.S. in 2014 including 929 who were caught in the wild. Most of the NHPs used in experiments are macaques; but marmosets, spider monkeys, and squirrel monkeys are also used, and baboons and chimpanzees are used in the US. As of 2015, there are approximately 730 chimpanzees in U.S. laboratories. In a survey in 2003, it was found that 89% of singly-housed primates exhibited self-injurious or abnormal stereotypyical behaviors including pacing, rocking, hair pulling, and biting among others. The first transgenic primate was produced in 2001, with the development of a method that could introduce new genes into a rhesus macaque. This transgenic technology is now being applied in the search for a


id: animal-testing-20260505-4
file: data/en.wikipedia.org/wiki/Animal_testing-4.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
The regulations that apply to animals in laboratories vary across species. In the U.S., under the Animal Welfare Act and the Guide for the Care and Use of Laboratory Animals (the Guide), published by the National Academy of Sciences, any procedure can be performed on an animal if it can be successfully argued that it is scientifically justified. Researchers are required to consult with the institution's veterinarian and its Institutional Animal Care and Use Committee (IACUC), which every research facility is obliged to maintain. The IACUC must ensure that alternatives, including non-animal alternatives, have been considered, that the experiments are not unnecessarily duplicative, and that pain relief is given unless it would interfere with the study. The IACUCs regulate all vertebrates in testing at institutions receiving federal funds in the USA. Although the Animal Welfare Act does not include purpose-bred rodents and birds, these species are equally regulated under Public Health Service policies that govern the IACUCs. The Public Health Service policy oversees the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC). The CDC conducts infectious disease research on nonhuman primates (due to end, according to an announcement in November 2025), rabbits, mice, and


id: animal-testing-20260505-5
file: data/en.wikipedia.org/wiki/Animal_testing-5.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
=== Numbers === Accurate global figures for animal testing are difficult to obtain; it has been estimated that 100 million vertebrates are experimented on around the world every year, 10–11 million of them in the EU. The Nuffield Council on Bioethics reports that global annual estimates range from 50 to 100 million animals. None of the figures include invertebrates such as shrimp and fruit flies.The USDA/APHIS has published the 2016 animal research statistics. Overall, the number of animals (covered by the Animal Welfare Act) used in research in the US rose 6.9% from 767,622 (2015) to 820,812 (2016). This includes both public and private institutions. By comparing with EU data, where all vertebrate species are counted, Speaking of Research estimated that around 12 million vertebrates were used in research in the US in 2016. A 2015 article published in the Journal of Medical Ethics, argued that the use of animals in the US has dramatically increased in recent years. Researchers found this increase is largely the result of an increased reliance on genetically modified mice in animal studies. In 1995, researchers at Tufts University Center for Animals and Public Policy estimated that 14–21 million animals were used in American laboratories


id: animal-testing-20260505-6
file: data/en.wikipedia.org/wiki/Animal_testing-6.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
In the U.S., Class A breeders are licensed by the U.S. Department of Agriculture (USDA) to sell animals for research purposes, while Class B dealers are licensed to buy animals from "random sources" such as auctions, pound seizure, and newspaper ads. Some Class B dealers have been accused of kidnapping pets and illegally trapping strays, a practice known as bunching. It was in part out of public concern over the sale of pets to research facilities that the 1966 Laboratory Animal Welfare Act was ushered in—the Senate Committee on Commerce reported in 1966 that stolen pets had been retrieved from Veterans Administration facilities, the Mayo Institute, the University of Pennsylvania, Stanford University, and Harvard and Yale Medical Schools. The USDA recovered at least a dozen stolen pets during a raid on a Class B dealer in Arkansas in 2003. Four states in the U.S.—Minnesota, Utah, Oklahoma, and Iowa—require their shelters to provide animals to research facilities. Fourteen states explicitly prohibit the practice, while the remainder either allow it or have no relevant legislation. In the European Union, animal sources are governed by Council Directive 86/609/EEC, which requires lab animals to be specially bred, unless the animal has been lawfully imported


id: animal-testing-20260505-7
file: data/en.wikipedia.org/wiki/Animal_testing-7.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
Regulations require that scientists use as few animals as possible, especially for terminal experiments. However, while policy makers consider suffering to be the central issue and see animal euthanasia as a way to reduce suffering, others, such as the RSPCA, argue that the lives of laboratory animals have intrinsic value. Regulations focus on whether particular methods cause pain and suffering, not whether their death is undesirable in itself. The animals are euthanized at the end of studies for sample collection or post-mortem examination; during studies if their pain or suffering falls into certain categories regarded as unacceptable, such as depression, infection that is unresponsive to treatment, or the failure of large animals to eat for five days; or when they are unsuitable for breeding or unwanted for some other reason. Methods of euthanizing laboratory animals are chosen to induce rapid unconsciousness and death without pain or distress. The methods that are preferred are those published by councils of veterinarians. The animal can be made to inhale a gas, such as carbon monoxide and carbon dioxide, by being placed in a chamber, or by use of a face mask, with or without prior sedation or anesthesia. Sedatives or anesthetics such as


id: animal-testing-20260505-8
file: data/en.wikipedia.org/wiki/Animal_testing-8.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
Genetic modification of animals to study disease. Transgenic animals have specific genes inserted, modified or removed, to mimic specific conditions such as single gene disorders, such as Huntington's disease. Other models mimic complex, multifactorial diseases with genetic components, such as diabetes, or even transgenic mice that carry the same mutations that occur during the development of cancer. These models allow investigations on how and why the disease develops, as well as providing ways to develop and test new treatments. The vast majority of these transgenic models of human disease are lines of mice, the mammalian species in which genetic modification is most efficient. Smaller numbers of other animals are also used, including rats, pigs, sheep, fish, birds, and amphibians. Studies on models of naturally occurring disease and condition. Certain domestic and wild animals have a natural propensity or predisposition for certain conditions that are also found in humans. Cats are used as a model to develop immunodeficiency virus vaccines and to study leukemia because their natural predisposition to FIV and Feline leukemia virus. Certain breeds of dog experience narcolepsy making them the major model used to study the human condition. Armadillos and humans are among only a few animal species


id: animal-testing-20260505-9
file: data/en.wikipedia.org/wiki/Animal_testing-9.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
Toxicology testing, also known as safety testing, is conducted by pharmaceutical companies testing drugs, or by contract animal testing facilities, such as Huntingdon Life Sciences, on behalf of a wide variety of customers. According to 2005 EU figures, around one million animals are used every year in Europe in toxicology tests; which are about 10% of all procedures. According to Nature, 5,000 animals are used for each chemical being tested, with 12,000 needed to test pesticides. The tests are conducted without anesthesia, because interactions between drugs can affect how animals detoxify chemicals, and may interfere with the results. Toxicology tests are used to examine finished products such as pesticides, medications, food additives, packing materials, and air freshener, or their chemical ingredients. Most tests involve testing ingredients rather than finished products, but according to BUAV, manufacturers believe these tests overestimate the toxic effects of substances; they therefore repeat the tests using their finished products to obtain a less toxic label. The substances are applied to the skin or dripped into the eyes; injected intravenously, intramuscularly, or subcutaneously; inhaled either by placing a mask over the animals and restraining them, or by placing them in an inhalation chamber; or administered orally, through


id: animal-testing-20260505-10
file: data/en.wikipedia.org/wiki/Animal_testing-10.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
metabolic tests, investigating pharmacokinetics—how drugs are absorbed, metabolized and excreted by the body when introduced orally, intravenously, intraperitoneally, intramuscularly, or transdermally. toxicology tests, which gauge acute, sub-acute, and chronic toxicity. Acute toxicity is studied by using a rising dose until signs of toxicity become apparent. Current European legislation demands that "acute toxicity tests must be carried out in two or more mammalian species" covering "at least two different routes of administration". Sub-acute toxicity is where the drug is given to the animals for four to six weeks in doses below the level at which it causes rapid poisoning, in order to discover if any toxic drug metabolites build up over time. Testing for chronic toxicity can last up to two years and, in the European Union, is required to involve two species of mammals, one of which must be non-rodent. efficacy studies, which test whether experimental drugs work by inducing the appropriate illness in animals. The drug is then administered in a double-blind controlled trial, which allows researchers to determine the effect of the drug and the dose-response curve. Specific tests on reproductive function, embryonic toxicity, or carcinogenic potential can all be required by law, depending on the result of


id: animal-testing-20260505-11
file: data/en.wikipedia.org/wiki/Animal_testing-11.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
The moral and ethical questions raised by performing experiments on animals are subject to debate, and viewpoints have shifted significantly over the 20th century. There remain disagreements about which procedures are useful for which purposes, as well as disagreements over which ethical principles apply to which species. A 2015 Gallup poll found that 67% of Americans were "very concerned" or "somewhat concerned" about animals used in research. A Pew poll taken the same year found 50% of American adults opposed the use of animals in research. Still, a wide range of viewpoints exist. The view that animals have moral rights (animal rights) is a philosophical position proposed by Tom Regan, among others, who argues that animals are beings with beliefs and desires, and as such are the "subjects of a life" with moral value and therefore moral rights. Regan still sees ethical differences between killing human and non-human animals, and argues that to save the former it is permissible to kill the latter. Likewise, a "moral dilemma" view suggests that avoiding potential benefit to humans is unacceptable on similar grounds, and holds the issue to be a dilemma in balancing such harm to humans to the harm done to animals


id: animal-testing-20260505-12
file: data/en.wikipedia.org/wiki/Animal_testing-12.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
=== Threats to researchers === Threats of violence to animal researchers are not uncommon. In 2006, a primate researcher at the University of California, Los Angeles (UCLA) shut down the experiments in his lab after threats from animal rights activists. The researcher had received a grant to use 30 macaque monkeys for vision experiments; each monkey was anesthetized for a single physiological experiment lasting up to 120 hours, and then euthanized. The researcher's name, phone number, and address were posted on the website of the Primate Freedom Project. Demonstrations were held in front of his home. A Molotov cocktail was placed on the porch of what was believed to be the home of another UCLA primate researcher; instead, it was accidentally left on the porch of an elderly woman unrelated to the university. The Animal Liberation Front claimed responsibility for the attack. As a result of the campaign, the researcher sent an email to the Primate Freedom Project stating "you win", and "please don't bother my family anymore". In another incident at UCLA in June 2007, the Animal Liberation Brigade placed a bomb under the car of a UCLA children's ophthalmologist who experiments on cats and rhesus monkeys; the bomb


id: animal-testing-20260505-13
file: data/en.wikipedia.org/wiki/Animal_testing-13.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
As the experimentation on animals increased, especially the practice of vivisection, so did criticism and controversy. In 1655, the advocate of Galenic physiology Edmund O'Meara said that "the miserable torture of vivisection places the body in an unnatural state". O'Meara and others argued pain could affect animal physiology during vivisection, rendering results unreliable. There were also objections ethically, contending that the benefit to humans did not justify the harm to animals. Early objections to animal testing also came from another angle—many people believed animals were inferior to humans and so different that results from animals could not be applied to humans. On the other side of the debate, those in favor of animal testing held that experiments on animals were necessary to advance medical and biological knowledge. Claude Bernard—who is sometimes known as the "prince of vivisectors" and the father of physiology, and whose wife, Marie Françoise Martin, founded the first anti-vivisection society in France in 1883—famously wrote in 1865 that "the science of life is a superb and dazzlingly lighted hall which may be reached only by passing through a long and ghastly kitchen". Arguing that "experiments on animals [. . .] are entirely conclusive for the toxicology and


id: animal-testing-20260505-14
file: data/en.wikipedia.org/wiki/Animal_testing-14.md
category: reference
title: Animal testing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_testing
date_saved: 2026-05-05T10:01:38.284993+00:00
instance: kb-cron
parent: animal-testing-20260505-0
summary:
Most scientists and governments state that animal testing should cause as little suffering to animals as possible, and that animal tests should only be performed when there is no alternative. The "Three Rs" are guiding principles for the use of animals in research in most countries. Whilst replacement of animals, i.e. alternatives to animal testing, is one of the principles, their scope is much broader. Although such principles have been welcomed as a step forwards by some animal welfare groups, they have also been criticized as both outdated by current research, and of little practical effect in improving animal welfare. The scientists and engineers at Harvard's Wyss Institute have created "organs-on-a-chip", including the "lung-on-a-chip" and "gut-on-a-chip". Researchers at cellasys in Germany developed a "skin-on-a-chip". These tiny devices contain human cells in a 3-dimensional system that mimics human organs. The chips can be used instead of animals in in vitro disease research, drug testing, and toxicity testing. Researchers have also begun using 3-D bioprinters to create human tissues for in vitro testing. Another non-animal research method is in silico or computer simulation and mathematical modeling which seeks to investigate and ultimately predict toxicity and drug effects on humans without using animals.


id: archival-research-20260505-0
file: data/en.wikipedia.org/wiki/Archival_research-0.md
category: reference
title: Archival research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archival_research
date_saved: 2026-05-05T10:01:39.554526+00:00
instance: kb-cron
parent: archival-research-20260505-0
summary:
Archival research is a type of research which involves seeking out and extracting evidence from archival records. These records may be held either in collecting institutions, such as libraries and museums, or in the custody of the organization (whether a government body, business, family, or other agency) that originally generated or accumulated them, or in that of a successor body (transferring, or in-house archives). Archival research can be contrasted with (1) secondary research (undertaken in a library or online), which involves identifying and consulting secondary sources relating to the topic of enquiry; and (2) with other types of primary research and empirical investigation such as fieldwork and experiment. == History of archives organizations == The oldest archives have been in existence for hundreds of years. For instance, in Europe, the General Archive of the Crown of Aragon was instituted in 1318, or the Vatican Secret Archives which were started in the 17th century and contain state papers, papal account books, and papal correspondence dating back to the 8th century. The Archives Nationales in France was founded in 1790 during the French Revolution and has holdings that date back to AD 625, and other European archives have a similar provenance. Archives


id: archival-research-20260505-1
file: data/en.wikipedia.org/wiki/Archival_research-1.md
category: reference
title: Archival research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archival_research
date_saved: 2026-05-05T10:01:39.554526+00:00
instance: kb-cron
parent: archival-research-20260505-0
summary:
=== Locating archival collections === Prior to online search, union catalogs were an important tool for finding materials in libraries and archives. In the United States, the National Union Catalog and the National Union Catalog of Manuscript Collections have been used by researchers to locate archives although much of its information has since been migrated to online systems. An increasing number of archival institutions can be found via an online search. In addition, portals such as Europeana, the Digital Public Library of America and the National Library of Australia's Trove provide links to member institutions. In the UK, JISC hosts the ArchivesHub, while the OCLC's ArchiveGrid provides an international portal for mostly library based institutions, which use MARC as a cataloguing tool for their holdings. The Association of Canadian Archivists (ACA) has partnered with the software company Artefactual to create ArchivesCanada, while the Australian Society of Archivists have used the same software for their Directory of Archives in Australia. Many other online search tools have been made available to facilitate search and discovery, including the Location Register of English Literary Manuscripts and Letters, the ArchiveSearch guide to archival materials in institutions in Cambridge, UK, and CARTOMAC: Archives littéraires d'Afrique. If


id: archival-research-20260505-2
file: data/en.wikipedia.org/wiki/Archival_research-2.md
category: reference
title: Archival research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archival_research
date_saved: 2026-05-05T10:01:39.554526+00:00
instance: kb-cron
parent: archival-research-20260505-0
summary:
A reading room is a space, usually within or near the archive, where users can consult archival materials under staff supervision. The unique, fragile, or sensitive nature of some materials sometimes requires the certain kinds of restrictions on their use, handling, and/or duplication. Many archives restrict what kinds of items can be brought into a reading room from outside, such as pencils, notepads, bags, and even clothing, to guard against theft or risk of damage to materials. Further restrictions may be placed on the number of materials that can be consulted at any given time, such as limiting a user to one box at a time and requiring all materials to be laid flat and visible at all times. Some archives provide basic supplies including scrap paper and pencils or foam wedges for supporting unusually large materials. Duplication services may be available at the archive although the policies, costs, and time required can vary. Increasingly, archives also allow users to use their own devices, such as handheld cameras, cell phones, and even scanners, to duplicate materials. The use of white or any other glove, while popular in television programs, is not necessarily required for handling archival documents, due to concerns


id: art-based-research-20260505-0
file: data/en.wikipedia.org/wiki/Art-based_research-0.md
category: reference
title: Art-based research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Art-based_research
date_saved: 2026-05-05T10:01:40.700649+00:00
instance: kb-cron
parent: art-based-research-20260505-0
summary:
Art-based research is a mode of formal qualitative inquiry that uses artistic processes in order to understand and articulate the subjectivity of human experience. == History == The term was first coined by Elliot Eisner, who was a professor of Art and Education at the Stanford Graduate School of Education and one of the United States' leading academic minds. Eisner used the term "art-based research" as the title of a conference presentation held at Stanford University in 1993. Subsequently, the concept of art-based research was defined by Shaun McNiff, professor of Creative Arts Therapies at Lesley College, as "the systematic use of the artistic process, the actual making of artistic expressions in all of the different forms of the arts, as a primary way of understanding and examining experience by both researchers and the people that they involve in their studies". It was later additionally defined as "research that uses the arts, in the broadest sense, to explore, understand, represent and even challenge human action and experience". Many practitioners of art-based research trace the origins of their approach to the work of German arts theorist and psychologist Rudolf Arnheim, and American philosopher Susanne Langer, both of whom elucidated the use


id: aaalac-international-20260505-0
file: data/en.wikipedia.org/wiki/AAALAC_International-0.md
category: reference
title: AAALAC International
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/AAALAC_International
date_saved: 2026-05-05T10:01:41.804867+00:00
instance: kb-cron
parent: aaalac-international-20260505-0
summary:
AAALAC International is a private, nonprofit organization headquartered in Frederick, Maryland, that promotes the humane treatment of animals in science through voluntary accreditation and assessment programs. The accreditation program started in 1965, when some veterinarians and researchers organized the American Association for Accreditation of Laboratory Animal Care, or AAALAC. In 1996, AAALAC changed its name to the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC International). The organization said the name change reflected the organization's growth in other countries and its commitment to enhancing life sciences and quality animal care around the world. Since 2016, the organization is officially known only by its acronym, AAALAC International. There are currently about 1,000 organizations worldwide accredited through its program. Along with meeting all applicable local and national regulations, AAALAC accredited institutions must also demonstrate that they are achieving the standards outlined in the Guide for the Care and Use of Laboratory Animals, a document published since 1996 by the National Research Council of the U.S. National Academy of Sciences. The Guide includes standards go beyond what is required by law. == See also == Animal welfare Animal testing American Association for Laboratory Animal Science, a U.S. nonprofit organization Animal


id: audit-study-20260505-0
file: data/en.wikipedia.org/wiki/Audit_study-0.md
category: reference
title: Audit study
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Audit_study
date_saved: 2026-05-05T10:01:58.929950+00:00
instance: kb-cron
parent: audit-study-20260505-0
summary:
A type of study used in economics, sociology, political science, and psychology, an audit study is one in which trained employees of the researcher ("auditors") are matched on all characteristics except the one being tested for discrimination. These auditors then apply for a service, be it a job, financial advice regarding their stock portfolio, housing, or a credit card, to test for discrimination. == Applications == Audit studies have been conducted to test the existence of discrimination in numerous occupations and services and in regards to multiple characteristics. For example, studies have been conducted to measure discrimination against racial minorities by real estate agents, racial discrimination in professional networking on LinkedIn and Twitter, requests on Airbnb, prices in online markets, emails to early childcare facilities as well as gender discrimination against women applying for restaurant jobs. Most employment-related audit studies have focused on overqualified college students applying for low-paying jobs during the summer. They have also been used to measure racial and gender discrimination in academia, racial discrimination in the low and high ends of the labor market, discrimination in social integration, and racial/ethnic discrimination in roommate selection. == Criticism == Audit studies have been criticized because the auditors may


id: autodidacticism-20260505-0
file: data/en.wikipedia.org/wiki/Autodidacticism-0.md
category: reference
title: Autodidacticism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Autodidacticism
date_saved: 2026-05-05T10:02:00.088315+00:00
instance: kb-cron
parent: autodidacticism-20260505-0
summary:
Autodidacticism (also autodidactism) or self-education (also self-learning, self-study, and self-teaching) is the practice of education without the guidance of teachers. Autodidacts are self-taught people who learn a subject through self-study. Autodidacticism may involve, complement, or be an alternative to formal education. Formal education itself may have a hidden curriculum that requires self-study for the uninitiated. Generally, autodidacts choose the subject they will study, their studying material, and the studying rhythm and time. Autodidacts may or may not have formal education, and their study may be either a complement or an alternative to formal education. Many notable contributions have been made by autodidacts. The self-learning curriculum is infinite. One may seek out alternative pathways in education and use these to gain competency; self-study may meet some prerequisite-curricula criteria for experiential education or apprenticeship. Self-education techniques can include reading educational books or websites, watching educational videos and listening to educational audio recordings, or by visiting infoshops. One uses some space as a learning space, where one uses critical thinking to develop study skills within the broader learning environment until they've reached an academic comfort zone. == Terminology == The term autodidact has its roots in the Ancient Greek words αὐτός (autós, lit.


id: autodidacticism-20260505-1
file: data/en.wikipedia.org/wiki/Autodidacticism-1.md
category: reference
title: Autodidacticism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Autodidacticism
date_saved: 2026-05-05T10:02:00.088315+00:00
instance: kb-cron
parent: autodidacticism-20260505-0
summary:
Autodidacticism is sometimes a complement of modern formal education. As a complement to formal education, students would be encouraged to do more independent work. Before the twentieth century, only a small minority of people received an advanced academic education. As stated by Joseph Whitworth in his influential report on industry and innovators dated from 1853, literacy rates were higher in the United States than in England. However, even in the U.S., most children were not completing high school. High school education was necessary to become a teacher. In modern times, a larger percentage of those completing high school also attended college, usually to pursue a professional degree, such as law or medicine, or a divinity degree. Collegiate teaching was based on the classics (Latin, philosophy, ancient history, theology) until the early nineteenth century. There were few if any institutions of higher learning offering studies in engineering or science before 1800. Institutions such as the Royal Society did much to promote scientific learning, including public lectures. In England, there were also itinerant lecturers offering their service, typically for a fee. Prior to the nineteenth century, there were many important inventors working as millwrights or mechanics who, typically, had received an elementary


id: autodidacticism-20260505-2
file: data/en.wikipedia.org/wiki/Autodidacticism-2.md
category: reference
title: Autodidacticism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Autodidacticism
date_saved: 2026-05-05T10:02:00.088315+00:00
instance: kb-cron
parent: autodidacticism-20260505-0
summary:
The first philosophical claim supporting an autodidactic program to the study of nature and God was in the philosophical novel Hayy ibn Yaqdhan (Alive son of the Vigilant), whose titular hero is considered the archetypal autodidact. The story is a medieval autodidactic utopia, a philosophical treatise in a literary form, which was written by the Andalusian philosopher Ibn Tufail in the 1160s in Marrakesh. It is a story about a feral boy, an autodidact prodigy who masters nature through instruments and reason, discovers laws of nature by practical exploration and experiments, and gains summum bonum through a mystical mediation and communion with God. The hero rises from his initial state of tabula rasa to a mystical or direct experience of God after passing through the necessary natural experiences. The focal point of the story is that human reason, unaided by society and its conventions or by religion, can achieve scientific knowledge, preparing the way to the mystical or highest form of human knowledge. Commonly translated as "The Self-Taught Philosopher" or "The Improvement of Human Reason", Ibn-Tufayl's story Hayy Ibn-Yaqzan inspired debates about autodidacticism in a range of historical fields from classical Islamic philosophy through Renaissance humanism and the European Enlightenment.


id: avian-ecology-field-methods-20260505-0
file: data/en.wikipedia.org/wiki/Avian_ecology_field_methods-0.md
category: reference
title: Avian ecology field methods
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Avian_ecology_field_methods
date_saved: 2026-05-05T10:02:01.276869+00:00
instance: kb-cron
parent: avian-ecology-field-methods-20260505-0
summary:
There are many field methods available for conducting avian ecological research. They can be divided into three types: counts, nest monitoring, and capturing and marking. == Basic counts == Basic bird counts are a good way to estimate population size, detect changes in population size or species diversity, and determine the cause of the changes if environmental or habitat data is collected as well. Basic bird counts can be completed fairly easily and inexpensively, and they provide general information about the status of a bird population. Birds can be directly counted on breeding colonies, and at roosts, flocks, or Leks. Large diurnal migrants, like many raptors, can be counted as they pass through migration bottlenecks. Small nocturnal migrants are harder to count, but many advances have been made in the use of radar and microphone arrays to identify and count them. === Point counts and area searches === Perhaps the simplest method of counting birds is called a "point count", in which a trained observer records all the birds seen and heard from a point count station for a set period of time. A series of point counts completed over a fixed route can then be compared to the results


id: braiding-knowledge-20260505-0
file: data/en.wikipedia.org/wiki/Braiding_knowledge-0.md
category: reference
title: Braiding knowledge
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Braiding_knowledge
date_saved: 2026-05-05T10:02:02.437237+00:00
instance: kb-cron
parent: braiding-knowledge-20260505-0
summary:
Braiding knowledge is a research framework that combines traditional knowledge with "Western" science to address contemporary issues. == Organizations == The following organizations center the use of braiding knowledge in their mission statements. === Center for Braiding Indigenous Knowledges and Science === The Center for Braiding Indigenous Knowledges and Science (CBIKS) was founded in 2023 with funding by the National Science Foundation’s Science and Technology Centers: Integrative Partnerships program by co-principal investigators: Sonya Atalay, Ora Marek-Martinez, Bonnie Newsom, and Jon Woodruff. The Center is located on the MIT campus with eight regional hubs across the U.S. and in Canada, Aotearoa New Zealand, and Australia. Research is fully community-driven and in full collaboration with community partners at all education levels. CBIKS is currently directed by Sonya Atalay. === Braiding Knowledge Project === The Braiding Knowledge Project, founded in 2021, is led by Melissa Tehee, Breanne Litts, and Rogelio Cardona-Rivera between Utah State University and the University of Utah with funding from the Spencer Foundation and the National Science Foundation. === Braiding Knowledges Canada (BKC) === BKC is a Canadian not-for-profit corporation established in 2019 that promotes decolonizing practices through place-based, community-driven environmental research. The corporation is supported by a five-year grant


id: nicole-brown-social-scientist-20260505-0
file: data/en.wikipedia.org/wiki/Nicole_Brown_(social_scientist)-0.md
category: reference
title: Nicole Brown (social scientist)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Nicole_Brown_(social_scientist)
date_saved: 2026-05-05T10:02:03.633185+00:00
instance: kb-cron
parent: nicole-brown-social-scientist-20260505-0
summary:
Nicole Brown (born 1976) is an Austrian and British writer and academic whose expertise lies with social research practice. She focuses on the development and pragmatics of research methods and approaches for data analysis as well as dissemination. == Education == Brown has a teaching qualification (2001), a Magister degree from the University of Vienna (2001), a master's degree in teaching from the UCL Institute of Education (2006), a diploma in translation from the University of London (2008). She has a 2018 postgraduate certificate in higher education, a 2020 masters degree in higher education, and a PhD in sociology, all from the University of Kent. == Career == Associate Professor and IOE Head of Research Ethics and Integrity at University College London, and Director of Social Research & Practice and Education Ltd. Brown researches physical and material representations of experiences, the generation of knowledge and use of metaphors to express what is difficult to express, and more generally, research methods and approaches to explore identity and body work. Brown is an editor for the Journal of Participatory Research Methods, Disability and Society, and The Qualitative Report. She is a long-standing member of methodologically-orientated organisations, such as the Pedagogy Network of


id: chronosequence-20260505-0
file: data/en.wikipedia.org/wiki/Chronosequence-0.md
category: reference
title: Chronosequence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chronosequence
date_saved: 2026-05-05T10:02:04.866584+00:00
instance: kb-cron
parent: chronosequence-20260505-0
summary:
A chronosequence describes a set of ecological sites that share similar attributes but represent different ages. A common assumption in establishing chronosequences is that no other variable besides age (such as various abiotic components and biotic components) has changed between sites of interest. Because this assumption cannot always be tested for environmental study sites, the use of chronosequences in field successional studies has recently been debated. == Applications == === Forest sciences === Since many processes in forest ecology take a long time (decades or centuries) to develop, chronosequence methods are used to represent and study the time-dependent development of a forest. Field data from a forest chronosequence can be collected in a short period of several months. === Soil science === Chronosequences used in soil studies consist of sites that have developed over different periods of time with relatively small differences in other soil-forming factors. Such groups of sites are used to assess the influence of time as a factor in pedogenesis. === Ecology === Chronosequences are often used to study the changes in plant communities during succession. A classic example of using chronosequences to study ecological succession is in the study of plant and microbial succession in recently


id: co-production-approach-20260505-0
file: data/en.wikipedia.org/wiki/Co-production_(approach)-0.md
category: reference
title: Co-production (approach)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Co-production_(approach)
date_saved: 2026-05-05T10:02:06.033625+00:00
instance: kb-cron
parent: co-production-approach-20260505-0
summary:
Co-production (or coproduction) is an approach in the development and delivery of public services and technology in which citizens and other key stakeholders and concepts in human society are implicitly involved in the process. In many countries, co-production is increasingly perceived as a new public administration paradigm as it involves a whole new thinking about public service delivery and policy development. In co-productive approaches, citizens are not only consulted, but are part of the conception, design, steering, and ongoing management of services. The concept has a long history, arising out of radical theories of knowledge in the 1970s, and can be applied in a range of sectors across society including health research, and science more broadly. == Definitions == An organisation called the Co-production Network for Wales describes co-production as "an asset-based approach to public services that enables people providing and people receiving services to share power and responsibility, and to work together in equal, reciprocal and caring relationships". According to Governance International, co-production is about "public service organisations and citizens making better use of each other's assets, resources and contributions". Co-production is designed to address real-world application of knowledge and forms part of what is termed Mode 2 of


id: co-production-approach-20260505-1
file: data/en.wikipedia.org/wiki/Co-production_(approach)-1.md
category: reference
title: Co-production (approach)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Co-production_(approach)
date_saved: 2026-05-05T10:02:06.033625+00:00
instance: kb-cron
parent: co-production-approach-20260505-0
summary:
=== Co-production of climate services === A disconnect exists between the climate information that is produced by science (in terms of weather forecasts and climate projections) and what is needed by users to make climate-resilient decisions. The mismatch usually relates to time scales, spatial scales, and metrics. Co-producing climate services, by bringing together producers and users of climate information for dialogue, can lead to the creation of new knowledge that is more appropriate for use in terms of being tailored and targeted to particular decisions. As in other fields, co-production of climate services, can create challenges due to differences in the incentives, priorities and languages of the various parties (often grouped into "producers" of information and "users" of information). Although there are no recipes for how to co-produce climate services, there are a number of building blocks and principles. == Concepts of co-production == Co-production is based on the production of own services and resources by citizens, completely or in part. It involves the willingness of citizens or users together with public services to design, implement and improve the delivery of services in order to innovate and transform public services. === Co-management === The concept of co-management implies the introduction


id: co-production-approach-20260505-2
file: data/en.wikipedia.org/wiki/Co-production_(approach)-2.md
category: reference
title: Co-production (approach)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Co-production_(approach)
date_saved: 2026-05-05T10:02:06.033625+00:00
instance: kb-cron
parent: co-production-approach-20260505-0
summary:
Funding and Commissioning: Commissioners of public money will need to change their established ways of doing things. Applying strict quantitative targets and stipulating rigid, short-term outputs with a mind to economic efficiency acts as a barrier to co-produced service models. In order to 'commission for change' narrow outputs need to be broadened and complemented by outcomes based commissioning. Generating evidence and making the case for co-production: The obvious reason why many commissioning frameworks favour outputs over outcomes is that they are simply measured, making it deceptively easy to evaluate success or failure. But real success is not easily measurable. Nor are many of the preventative benefits of co-production easy to quantify. Making the case for co-production and capturing its complex and myriad benefits is a key challenge. Taking successful approaches to scale: It is fair to say that the majority of examples where co-production is being successfully practiced take place at a local scale. To a great extent this has been instrumental to their success; they are rooted in local realities, have grown organically from the ground based on local assets and ideas and emphasise the importance of face-to-face relationships. There is a potential tension to be overcome here; ensuring


id: co-production-approach-20260505-3
file: data/en.wikipedia.org/wiki/Co-production_(approach)-3.md
category: reference
title: Co-production (approach)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Co-production_(approach)
date_saved: 2026-05-05T10:02:06.033625+00:00
instance: kb-cron
parent: co-production-approach-20260505-0
summary:
== Selected co-production bibliography == Alford, J. (1998), A public management road less traveled: clients as co-producers of public services. Australian Journal of Public Administration, 57 (4), 128-137. Alford, J. (2007), Engaging public sector clients: from service delivery to co-production. Houndmills, Basingstoke: Palgrave Macmillan. Barnes, M., Harrison, S., Mort, M., Shardlow, P. and Wistow G. (1999), 'The new management of community care: users groups, citizenship and co-production' in G.Stoker, New Management of British Local Governance. Houndmills: Macmillan. Tony Bovaird (2007), "Beyond engagement and participation – user and community co-production of public services", Public Administration Review, 67 (5): 846-860 (2007). Tony Bovaird and Elke Loeffler (2010), "User and community co-production of public services and public policies through collective decision-making: the role of emerging technologies" in T. Brandsen and Marc Holzer (Eds), The Future of Governance. Newark, NJ: National Center for Public Performance. Tony Bovaird and Elke Loeffler (2012), "From Engagement to Co-production: How Users and Communities Contribute to Public Services" in Taco Brandsen and Victor Pestoff (Eds), New Public Governance, the Third Sector and Co-Production. London: Routledge. Matthew Horne and Tom Shirley (2009), Co-production in public services: a new partnership with citizens. London: Cabinet Office. Roger Dunston, Alison Lee, David Boud,


id: community-engaged-research-20260505-0
file: data/en.wikipedia.org/wiki/Community-engaged_research-0.md
category: reference
title: Community-engaged research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Community-engaged_research
date_saved: 2026-05-05T10:02:07.181236+00:00
instance: kb-cron
parent: community-engaged-research-20260505-0
summary:
Community-engaged research (CEnR) is the process of working collaboratively with groups of people affiliated by geographic proximity, special interests, or similar situations with respect to issues affecting their well-being. One of the most widely used forms of community-engaged research is community-based participatory research (CBPR), though it also encompasses action research and participatory action research. Another form of community-engaged research is integrated knowledge translation (iKT), defined as "an approach to doing research that applies the principles of knowledge translation to the entire research process". The iKT evolves around the concept of engaging different levels of knowledge users (community members, organizations working in the community, and policy makers) as equal partners in the research activities so that research outputs are more relevant to, and more likely to be useful to, the knowledge users. == History == Community-engaged research arose in response to historical abuse of marginalized people by researchers, who failed to consider the needs of the community and potential benefits of the research. Types of CEnR include action research, community-based participatory research (CBPR), and participatory action research (PAR). The field of CEnR has grown rapidly since 2005. == Process == Community-engaged research is planned in partnership with the community that is


id: cross-sectional-study-20260505-0
file: data/en.wikipedia.org/wiki/Cross-sectional_study-0.md
category: reference
title: Cross-sectional study
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cross-sectional_study
date_saved: 2026-05-05T10:02:08.440904+00:00
instance: kb-cron
parent: cross-sectional-study-20260505-0
summary:
In medical research, epidemiology, social science, and biology, a cross-sectional study (also known as a cross-sectional analysis, transverse study, prevalence study) is a type of research design that analyzes data from a population, or a representative subset, at a specific point in time—that is, cross-sectional data. In economics, cross-sectional studies typically involve the use of cross-sectional regression, in order to sort out the existence and magnitude of causal effects of one independent variable upon a dependent variable of interest at a given point in time. They differ from time series analysis, in which the behavior of one or more economic aggregates is traced through time. In medical research, cross-sectional studies differ from case-control studies in that they aim to provide data on the entire population under study, whereas case-control studies typically include only individuals who have developed a specific condition and compare them with a matched sample, often a tiny minority, of the rest of the population. Cross-sectional studies are descriptive studies (neither longitudinal nor experimental). Unlike case-control studies, they can be used to describe, not only the odds ratio, but also absolute risks and relative risks from prevalences (sometimes called prevalence risk ratio, or PRR). They may be used


id: cross-sectional-study-20260505-1
file: data/en.wikipedia.org/wiki/Cross-sectional_study-1.md
category: reference
title: Cross-sectional study
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cross-sectional_study
date_saved: 2026-05-05T10:02:08.440904+00:00
instance: kb-cron
parent: cross-sectional-study-20260505-0
summary:
== Economics == In economics, cross-sectional analysis has the advantage of avoiding various complicating aspects of the use of data drawn from various points in time, such as serial correlation of residuals. It also has the advantage that the data analysis itself does not need an assumption that the nature of the relationships between variables is stable over time, though this comes at the cost of requiring caution if the results for one time period are to be assumed valid at some different point in time. An example of cross-sectional analysis in economics is the regression of money demand—the amounts that various people hold in highly liquid financial assets—at a particular time upon their income, total financial wealth, and various demographic factors. Each data point is for a particular individual or family, and the regression is conducted on a statistical sample drawn at one point in time from the entire population of individuals or families. In contrast, an intertemporal analysis of money demand would use data on an entire country's holdings of money at each of various points in time, and would regress that on contemporaneous (or near-contemporaneous) income, total financial wealth, and some measure of interest rates. The cross-sectional


id: cross-sequential-study-20260505-0
file: data/en.wikipedia.org/wiki/Cross-sequential_study-0.md
category: reference
title: Cross-sequential study
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cross-sequential_study
date_saved: 2026-05-05T10:02:09.630502+00:00
instance: kb-cron
parent: cross-sequential-study-20260505-0
summary:
A cross-sequential design is a research method that combines both a longitudinal design and a cross-sectional design. It aims to correct for some of the problems inherent in the cross-sectional and longitudinal designs. In a cross-sequential design (also called an "accelerated longitudinal" or "convergence" design), a researcher wants to study development over some large period of time within the lifespan. Rather than studying particular individuals across that whole period of time (e.g. 20–60 years) as in a longitudinal design, or multiple individuals of different ages at one time (e.g. 20, 25, 30, 35, 40, 45, 50, 55, and 60 years) as in a cross-sectional design, the researcher chooses a smaller time window (e.g. 20 years) to study multiple individuals of different starting ages. An example of a cross-sequential design is shown in the table below. In this table, over a span of 10 years, from 2000 to 2010, 7 overlapping cohorts with different starting ages could be studied to provide information on the whole span of development from ages 20 to 60. This design has been used in studies to investigate career trajectories in academia and other phenomena. == References ==


id: customer-foresight-20260505-0
file: data/en.wikipedia.org/wiki/Customer_foresight-0.md
category: reference
title: Customer foresight
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Customer_foresight
date_saved: 2026-05-05T10:02:10.845215+00:00
instance: kb-cron
parent: customer-foresight-20260505-0
summary:
Customer foresight is a new field of applied research. It aims to understand future consumer preferences and wishes with regard to tomorrow's products and services. It does so by combining customer research and foresight research elements. Customer foresight can be conceived as an interaction with projected future markets through selected customers by understanding their wishes and attitudes, ideas and visions as well as their perception of signals and drivers of change. Even though the concept cannot predict the future, it enables companies to prepare for different future scenarios and thus improves strategy and decision-making processes. == Definition and classification == As the future combines both continuity and change, not everything one knows today will disappear tomorrow. Some things will change significantly while others will not. But even today, research reveals that numerous inventions fail due to a lack of customer centricity. Consequently, anticipating future customer needs and behaviors constitutes a challenge when developing future product portfolios. This is especially relevant for industries with long planning cycles because these industries have to develop value propositions today for the customers of tomorrow. However, this involves dealing with many unknowns e.g. future everyday life or future consumption patterns. This is why, customer foresight


id: data-storage-tag-20260505-0
file: data/en.wikipedia.org/wiki/Data_storage_tag-0.md
category: reference
title: Data storage tag
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Data_storage_tag
date_saved: 2026-05-05T10:02:12.030778+00:00
instance: kb-cron
parent: data-storage-tag-20260505-0
summary:
A data storage tag (DST), also sometimes known as an archival tag, is a combination of a data logger and multiple sensors that record data at predetermined intervals. DSTs usually have a large memory size and a long lifetime: most are supported by batteries that allow the tag to record positions for several years. Alternatively some tags are solar powered and allow the scientist to set their own interval; this then allows data to be recorded for significantly longer than battery-only powered tags. == Operation == Data storage tags can have a variety of sensors; temperature, depth, light, salinity, pressure, pitch and roll, GPS, magnetic and compass. They can be used internally or externally in fish, marine animals or research animals. They are also used in other industries such as the food and beverage industry. At the end of the monitoring period, the loggers can be connected to a computer and the data uploaded for analysis. Data collected by data storage tags can be used to infer locations of the animal when it is at large. == Deployment == Archival tags archive data to internal memory. Once they are recovered the data is then extracted by the researcher. The tag


id: design-science-20260505-0
file: data/en.wikipedia.org/wiki/Design_science-0.md
category: reference
title: Design science
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Design_science
date_saved: 2026-05-05T10:02:13.249584+00:00
instance: kb-cron
parent: design-science-20260505-0
summary:
Design science refers to a scientific, i.e. rational and systematic, approach to designing. An early concept of design science was introduced in 1957 by R. Buckminster Fuller who defined it as a systematic form of designing which he applied especially in innovative engineering design. The concept has been more broadly defined by the Design Science journal as “quantitative and qualitative research in the creation of artifacts and systems, and their embedding in our physical, virtual, psychological, economic, and social environment”. == Design-science relationship == There has been recurrent concern to differentiate design from science. Nigel Cross differentiated between scientific design, design science and a science of design. A science of design (the scientific study of design) does not require or assume that the acts of designing are themselves scientific, and an increasing number of research programs take this view. To some extent the two uses of the term design science (systematic designing and the study of designing) have co-mingled to the point where there can be some confusion, and design science sometimes may be referred to either as meaning a science of design or design as a science. == A science of design == Herbert A. Simon's The Sciences of


id: design-science-methodology-20260505-0
file: data/en.wikipedia.org/wiki/Design_science_(methodology)-0.md
category: reference
title: Design science (methodology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Design_science_(methodology)
date_saved: 2026-05-05T10:02:14.418805+00:00
instance: kb-cron
parent: design-science-methodology-20260505-0
summary:
Design science research (DSR) is a research paradigm focusing on the development and validation of prescriptive knowledge in information science. Herbert Simon distinguished the natural sciences, concerned with explaining how things are, from design sciences which are concerned with how things ought to be, that is, with devising artifacts to attain goals. Design science research methodology (DSRM) refers to the research methodologies associated with this paradigm. It spans the methodologies of several research disciplines, for example information technology, which offers specific guidelines for evaluation and iteration within research projects. DSR focuses on the development and performance of (designed) artifacts with the explicit intention of improving the functional performance of the artifact. DSRM is typically applied to categories of artifacts including algorithms, human/computer interfaces, design methodologies (including process models) and languages. Its application is most notable in the Engineering and Computer Science disciplines, though is not restricted to these and can be found in many disciplines and fields. DSR, or constructive research, in contrast to explanatory science research, has academic research objectives generally of a more pragmatic nature. Research in these disciplines can be seen as a quest for understanding and improving human performance. Such renowned research institutions as the MIT


id: design-science-methodology-20260505-1
file: data/en.wikipedia.org/wiki/Design_science_(methodology)-1.md
category: reference
title: Design science (methodology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Design_science_(methodology)
date_saved: 2026-05-05T10:02:14.418805+00:00
instance: kb-cron
parent: design-science-methodology-20260505-0
summary:
Artifacts within DSR are perceived to be knowledge containing. This knowledge ranges from the design logic, construction methods and tool to assumptions about the context in which the artifact is intended to function (Gregor, 2002). The creation and evaluation of artifacts thus forms an important part in the DSR process which was described by Hevner et al., (2004) and supported by March and Storey (2008) as revolving around “build and evaluate”. DSR artifacts can broadly include: models, methods, constructs, instantiations and design theories (March & Smith, 1995; Gregor 2002; March & Storey, 2008, Gregor and Hevner 2013), social innovations, new or previously unknown properties of technical/social/informational resources (March, Storey, 2008), new explanatory theories, new design and developments models and implementation processes or methods (Ellis & Levy 2010). == A three-cycle view == DSR can be seen as an embodiment of three closely related cycles of activities. The relevance cycle initiates DSR with an application context that not only provides the requirements for the research as inputs but also defines acceptance criteria for the ultimate evaluation of the research results. The rigor cycle provides past knowledge to the research project to ensure its innovation. It is incumbent upon the researchers to


id: design-based-research-20260505-0
file: data/en.wikipedia.org/wiki/Design-based_research-0.md
category: reference
title: Design-based research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Design-based_research
date_saved: 2026-05-05T10:02:15.526914+00:00
instance: kb-cron
parent: design-based-research-20260505-0
summary:
Design-based research (DBR) is a type of research methodology used by researchers in the learning sciences, which is a sub-field of education. The basic process of DBR involves developing solutions (called "interventions") to problems. Then, the interventions are put to use to test how well they work. The iterations may then be adapted and re-tested to gather more data. The purpose of this approach is to generate new theories and frameworks for conceptualizing learning, instruction, design processes, and educational reform. Data analysis often takes the form of iterative comparisons. == Role within the learning sciences == Methodologically, the learning sciences differs from other fields in educational research. It focuses on the study of learners, their localities, and their communities. The design-based research methodology is often used by learning scientists in their inquiries because this methodological framework considers the subject of study to be a complex system involving emergent properties that arise from the interaction of more variables than are initially known to researchers, including variables stemming from the researchers themselves (Brown, 1992). Rather than attempting to isolate all the various factors that impact learning as in traditional research, the learning sciences employ design based research methodologies which appeal to an


id: electric-cell-substrate-impedance-sensing-20260505-0
file: data/en.wikipedia.org/wiki/Electric_cell-substrate_impedance_sensing-0.md
category: reference
title: Electric cell-substrate impedance sensing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Electric_cell-substrate_impedance_sensing
date_saved: 2026-05-05T10:02:16.654964+00:00
instance: kb-cron
parent: electric-cell-substrate-impedance-sensing-20260505-0
summary:
Electric cell-substrate impedance sensing or ECIS (a trademark of Applied BioPhysics Inc.) refers to a non-invasive biophysical approach to monitor living animal cells in vitro, i.e. within a well-defined laboratory environment. In ECIS the cells are grown on the surface of small and planar gold-film electrodes, which are deposited on the bottom of a cell culture dish (Petri dish). The AC impedance of the cell-covered electrode is then measured at one or several frequencies as a function of time. Due to the insulating properties of their membranes the cells behave like dielectric particles so that the impedance increases with increasing coverage of the electrode until a confluent (i.e. continuous) layer of cells is established. In confluent cell layers the measured impedance is mainly determined by the three-dimensional shape of the cells. If cell shape changes occur, the current pathways through and around the cell bodies change as well, leading to a corresponding increase or decrease of impedance. Thus, by recording time-resolved impedance measurements, cell shape changes can be followed in real time with sub-microscopic resolution and can be used for bioanalytic purposes. As the shape of animal cells responds very sensitively to alterations in metabolism as well as chemical, biological


id: field-trip-20260505-0
file: data/en.wikipedia.org/wiki/Field_trip-0.md
category: reference
title: Field trip
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Field_trip
date_saved: 2026-05-05T10:02:17.862922+00:00
instance: kb-cron
parent: field-trip-20260505-0
summary:
A field trip or excursion is a journey by a group of associated peers, such as coworkers or school students, to a place away from their normal environment for the purpose of education or leisure, either within their country or abroad. When arranged by a school administration for students, it is also known as school trip in the United Kingdom, Australia, Kenya, New Zealand and Bangladesh, and school tour in Ireland. A 2022 study, which used randomized controlled trial data, found that culturally enriching field trips led students to show a greater interest in arts, greater tolerance for people with different views, and boosted their educational outcomes. == Overview == The purpose of the field trip is usually observation for education, non-experimental research or to provide students with experiences outside their everyday activities, such as going camping with teachers and their classmates. The aim of this research is to observe the subject in its natural state and possibly collect samples. It is seen that more-advantaged children may have already experienced cultural institutions outside of school, and field trips provide common ground between more-advantaged and less-advantaged children to share the same cultural experiences. Field trips often involve three steps: preparation, activities


id: force-matching-20260505-0
file: data/en.wikipedia.org/wiki/Force_matching-0.md
category: reference
title: Force matching
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Force_matching
date_saved: 2026-05-05T10:02:19.049219+00:00
instance: kb-cron
parent: force-matching-20260505-0
summary:
Force matching is a research method consisting of test subjects attempting to produce a set forces that are equal to a set of more reliable reference forces. == Types == === Biomechanical === A subject’s maximum voluntary contraction (MVC) is recorded and used to normalize both reference forces and results between subjects. During the test subjects are assisted in producing a reference force using various types of feedback (static weight or visual display of force generated). This is followed by an attempt of the subject to generate the reference force without assistance. The duration for both reference and matching tasks is usually four seconds. Results are taken as a mean value of force generated over a time interval set by the researcher. Time intervals are generally one second long and near the end of the attempt. Reference forces are typically set as a percentage of a subject’s MVC while error is typically reported as a percentage of a subject’s MVC. === Atomic === It is one of the effective research method to obtain realistic classical interatomic potential or force field for molecular dynamics simulation with high degree of transferability for systems which the first principles or ab initio method is


id: frascati-manual-20260505-0
file: data/en.wikipedia.org/wiki/Frascati_Manual-0.md
category: reference
title: Frascati Manual
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Frascati_Manual
date_saved: 2026-05-05T10:02:20.224055+00:00
instance: kb-cron
parent: frascati-manual-20260505-0
summary:
The Frascati Manual is a document setting forth the methodology for collecting statistics about research and development. The Manual was prepared and published by the Organisation for Economic Co-operation and Development. == Contents == The Frascati Manual classifies budgets according to what is done, what is studied, and who is studying it. For example, an oral history project conducted by a religious organization would be classified as being basic research, in the field of humanities (the sub-category of history), and performed by a non-governmental, non-profit organization. === Three forms of research === The manual gives definitions for: basic research, applied research, Research and development; research personnel: researchers, technicians, auxiliary personnel. The Frascati Manual classifies research into three categories: Basic research is experimental or theoretical work undertaken primarily to acquire new knowledge of the underlying foundations of phenomena and observable facts, without any particular application or use in view. Applied research is original investigation undertaken in order to acquire new knowledge. It is, however, directed primarily towards a specific, practical aim or objective. Experimental development is systematic work, drawing on knowledge gained from research and practical experience and producing additional knowledge, which is directed to producing new products or processes or


id: grounded-theory-20260505-0
file: data/en.wikipedia.org/wiki/Grounded_theory-0.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
Grounded theory is a systematic methodology that has been largely applied to qualitative research conducted by social scientists. The methodology involves the construction of hypotheses and theories through the analysis of data and inductive reasoning. The methodology contrasts with the hypothetico-deductive model used in traditional scientific research. A study based on grounded theory is likely to begin with a question, or even just with the collection of qualitative data. As researchers review the data collected, ideas or concepts become apparent to the researchers. These ideas/concepts are said to "emerge" from the data. The researchers tag those ideas/concepts with codes that succinctly summarize the ideas/concepts. As more data are collected and re-reviewed, codes can be grouped into higher-level concepts and then into categories. These categories become the basis of a hypothesis or a new theory. Thus, grounded theory is quite different from the traditional scientific model of research, where the researcher chooses an existing theoretical framework, develops one or more hypotheses derived from that framework, and only then collects data for the purpose of assessing the validity of the hypotheses. == Background == Grounded theory is a general research methodology, a way of thinking about and conceptualizing data. It is used


id: grounded-theory-20260505-1
file: data/en.wikipedia.org/wiki/Grounded_theory-1.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
== Premise == Grounded theory provides methods for generating hypotheses from qualitative data. After hypotheses are generated, it is up to other researchers to attempt to sustain or reject those hypotheses. Questions asked by the qualitative researcher employing grounded theory include "What is going on?" and "What is the main problem of the participants, and how are they trying to solve it?" Researchers using grounded theory methods do not aim for the "truth." Rather, those researchers try to conceptualize what has been taking place in the lives of study participants. When applying grounded theory methods, the researcher does not formulate hypotheses in advance of data collection as is often the case in traditional research, otherwise the hypotheses would be ungrounded in the data. Hypotheses are supposed to emerge from the data. A goal of the researcher employing grounded theory methods is that of generating concepts that explain the way people resolve their central concerns regardless of time and place. These concepts organize the ground-level data. The concepts become the building blocks of hypotheses. The hypotheses become the constituents of a theory. In most behavioral research endeavors, persons or patients are units of analysis, whereas in grounded theory the unit of


id: grounded-theory-20260505-2
file: data/en.wikipedia.org/wiki/Grounded_theory-2.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
=== Coding === Coding places incidents into categories and then creates one or more hierarchies out of these categories in terms of categories and subcategories or properties of a categories. A property might be on a continuum such as from low to high, this may be referred to as a dimension. Constant comparison where categories are continually compared to one another is used to create both subcategories and properties. There is some variation in the meanings of the terms code, concept and category with some authors viewing a code as identical to category while others consider a concept to be more abstract than a code, which a code being more like a substantive code. Different researchers have identified different types of codes and encourage different methods of coding, with Strauss and Glaser both going on to extend their work with different forms of coding. The core variable explains most of the participants' main concern with as much variation as possible. It has the most powerful properties to picture what's going on, but with as few properties as possible needed to do so. A popular type of core variable can be theoretically modeled as a basic social process that accounts for


id: grounded-theory-20260505-3
file: data/en.wikipedia.org/wiki/Grounded_theory-3.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
=== Serendipity pattern === Building on the work of sociologist Robert K. Merton, his idea of serendipity patterns has come to be applied in grounded theory research. Serendipity patterns refer to fairly common experiences when observing the world. Serendipity patterns include unanticipated and anomalous events. These patterns can become the impetus for the development of a new theory or the extension of an existing theory. Merton also coauthored (with Elinor Barber) The Travels and Adventures of Serendipity, which traces the origins and uses of the word "serendipity" since it was coined. The book is "a study in sociological semantics and the sociology of science," as the subtitle declares. Merton and Barber further develop the idea of serendipity as scientific "method," as contrasted with purposeful discovery by experiment or retrospective prophecy. === Sorting === In the next step memos are sorted, which is the key to formulating a theory that could be clearly presented to others. Sorting puts fractured data back together. During sorting new ideas can emerge. The new ideas can, in turn, be recorded in new memos, giving rise to the memo-on-memos phenomenon. Sorting memos can help generate theory that explains the main action in the studied area. A


id: grounded-theory-20260505-4
file: data/en.wikipedia.org/wiki/Grounded_theory-4.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
=== Constructivist grounded theory === A later version of grounded theory called constructivist grounded theory, which is rooted in pragmatism and constructivist epistemology, assumes that neither data nor theories are discovered, but are constructed by researchers as a result of their interactions with the field and study participants. Proponents of this approach include Kathy Charmaz and Antony Bryant. In an interview, Charmaz justified her approach as follows: "Grounded theory methodology had been under attack. The postmodern critique of qualitative research had weakened its legitimacy and narrative analysts criticized grounded theory methodology for fragmenting participants' stories. Hence, grounded theory methodology was beginning to be seen as a dated methodology and some researchers advocated abandoning it. I agreed with much of the epistemological critique of the early versions of grounded theory methodology by people like Kenneth Gergen. However, I had long thought that the strategies of grounded theory methodology, including coding, memo writing, and theoretical sampling were excellent methodological tools. I saw no reason to discard these tools and every reason to shift the epistemological grounds on which researchers used them." Data are co-constructed by the researcher and study participants, and colored by the researcher's perspectives, values, privileges, positions, interactions, and geographical


id: grounded-theory-20260505-5
file: data/en.wikipedia.org/wiki/Grounded_theory-5.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
== Criticisms == Grounded theory has been criticized based on the scientific idea of what a theory is. Thomas and James, for example, distinguish the ideas of generalization, overgeneralization, and theory, noting that some scientific theories explain a broad range of phenomena succinctly, which grounded theory does not. Thomas and James observed that "The problems come when too much is claimed for [for a theory], simply because it is empirical; problems come in distinguishing generalization from over-generalization, narrative from induction." They also write that grounded theory advocates sometimes claim to find causal implications when in truth they only find an association. There has been criticism of grounded theory on the grounds that it opens the door to letting too much researcher subjectivity enter. The authors just cited suggest that it is impossible to free oneself of preconceptions in the collection and analysis of data in the way that Glaser and Strauss assert is necessary. Popper also undermines grounded theory's idea that hypotheses arise from data unaffected by prior expectations. Popper wrote that "objects can be classified and can become similar or dissimilar, only in this way--by being related to needs and interests." Observation is always selective, based on past research


id: grounded-theory-20260505-6
file: data/en.wikipedia.org/wiki/Grounded_theory-6.md
category: reference
title: Grounded theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Grounded_theory
date_saved: 2026-05-05T10:02:21.462775+00:00
instance: kb-cron
parent: grounded-theory-20260505-0
summary:
== Further reading == Bryant, A. & Charmaz, K. (Eds.) (2007) The SAGE Handbook of Grounded Theory. Los Angeles: Sage. Birks, M. & Mills, J. (2015) Grounded Theory: A practical Guide. London: SAGE Publications. Charmaz, K. (2000). Constructing Grounded Theory: A Practical Guide Through Qualitative Analysis. Thousand Oaks, CA: Sage Publications. Chun Tie, Ylona, Birks, Melanie, and Francis, Karen (2019) Grounded theory research: a design framework for novice researchers. SAGE Open Medicine, 7. pp. 1–8. Clarke, A. (2005). Situational Analysis: Grounded Theory After the Postmodern Turn. Thousand Oaks, CA: Sage Publications. Glaser, B. (1992). Basics of grounded theory analysis. Mill Valley, CA: Sociology Press. Goulding, C. (2002). Grounded Theory: A Practical Guide for Management, Business and Market Researchers. London: Sage. Kelle, Udo (2005). "Emergence" vs. "Forcing" of Empirical Data? A Crucial Problem of "Grounded Theory" Reconsidered. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research [On-line Journal], 6(2), Art. 27, paragraphs 49 & 50. [2] Morse, J. M., Stern, P. N., Corbin, J., Bowers, B., Charmaz, K. & Clarke, A. E. (Eds.) (2009). Developing Grounded Theory: The Second Generation. Walnut Creek: Left Coast Press. Mey, G. & Mruck, K. (Eds.) (2007). Grounded Theory Reader. Historical Social Research, Suppl. 19. 337 pages.


id: health-risk-assessment-20260505-0
file: data/en.wikipedia.org/wiki/Health_risk_assessment-0.md
category: reference
title: Health risk assessment
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Health_risk_assessment
date_saved: 2026-05-05T10:02:22.671106+00:00
instance: kb-cron
parent: health-risk-assessment-20260505-0
summary:
A health risk assessment (also referred to as a health risk appraisal and health & well-being assessment) is a questionnaire about a person's medical history, demographic characteristics and lifestyle. It is one of the most widely used screening tools in the field of health promotion and is often the first step in multi-component health promotion programs. == Definition == A health risk assessment (HRA) is a health questionnaire, used to provide individuals with an evaluation of their health risks and quality of life. Commonly a HRA incorporates three key elements – an extended questionnaire, a risk calculation or score, and some form of feedback, i.e. face-to-face with a health advisor or an automatic online report. The Centers for Disease Control and Prevention define a HRA as: "a systematic approach to collecting information from individuals that identifies risk factors, provides individualised feedback, and links the person with at least one intervention to promote health, sustain function and/or prevent disease". There is a range of different HRAs available for adults and children. Some target specific populations. For example, in the US, Medicare HRAs ask seniors about their ability to perform daily activities. Medicaid assessments ask questions about health-care access, availability of food,


id: health-risk-assessment-20260505-1
file: data/en.wikipedia.org/wiki/Health_risk_assessment-1.md
category: reference
title: Health risk assessment
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Health_risk_assessment
date_saved: 2026-05-05T10:02:22.671106+00:00
instance: kb-cron
parent: health-risk-assessment-20260505-0
summary:
== History == The original concept of the HRA can be traced back to the decision by the assistant Surgeon General of the United States to conduct a study to determine the probable 10-year lifespan of individuals based on lifestyles and predisposed conditions. The project, led by Lewis C. Robbins, MD, of the Public Health Service, was the Framingham study. The study was based on in-depth longitudinal studies of 5,000 families in Framingham, Massachusetts, that continues to this day under funding from the National Institutes of Health. Dr. Robbins left the Public Health Service and joined Methodist Hospital in Indianapolis where, working with Jack Hall, M.D., he developed the first set of health hazard tables. This culminated in the publication of How to Practice Prospective Medicine in 1970 – a guide for practising physicians, which outlined the health risk assessment questionnaire, risk computations and patient feedback strategies. During the 1960s, some researchers in California formed the Human Population Laboratory (HPL) to investigate factors contributing to quality of life. Inspired by a research article reporting on the HPL's Alameda County Study on the best lifestyle practices for good health, Don R. Hall, DrPH, developed a Health Age Assessment algorithm on a


id: implementation-research-20260505-0
file: data/en.wikipedia.org/wiki/Implementation_research-0.md
category: reference
title: Implementation research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Implementation_research
date_saved: 2026-05-05T10:02:23.878384+00:00
instance: kb-cron
parent: implementation-research-20260505-0
summary:
Implementation research is the systematic study of methods that support the application of research findings and other evidence-based knowledge into policy and practice. It aims to understand the most effective pathways from research to practical application, particularly in areas such as health, education, psychology and management. Intervention research, also known as intervention science, evaluates how various interventions or approaches are adopted and applied in "real world" settings in order to establish an understanding of their effectiveness in different contexts. == Public health == In the context of public health, the World Health Organization (WHO) describes implementation research as a form of research which "addresses implementation bottlenecks, identifies optimal approaches for a particular setting, and promotes the uptake of research findings: ultimately, it leads to improved health care and its delivery." The WHO identifies four notable characteristics of implementation research: it is systematic, multidisciplinary, contextual, and complex. More broadly, implementation research has been defined as "the scientific inquiry into questions concerning implementation – the act of carrying an intention into effect, which in health research can be policies, programmes, or individual practices (collectively called interventions)." To guide, understand, and evaluate the implementation of these interventions in a systematic way, public health


id: incompatibility-thesis-20260505-0
file: data/en.wikipedia.org/wiki/Incompatibility_thesis-0.md
category: reference
title: Incompatibility thesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Incompatibility_thesis
date_saved: 2026-05-05T10:02:25.084785+00:00
instance: kb-cron
parent: incompatibility-thesis-20260505-0
summary:
Incompatibility thesis is an argument in research methodology about incompatibility of quantitative research and qualitative research paradigms in the same research. This thesis is based on philosophies of post-structuralism and post-modernism (among others). Arguments from those philosophies support exclusive superiority of one orientation (usually, the qualitative one) are oppose mixing it with quantitative research (as is advocated by the proponents of mixed-method research who support the compatibility thesis). == Information == Incompatibilists maintain that problems arise not so much at the level of practice, but at the level of epistemological paradigms. In particular, they propose that quantitative and qualitative methods are incompatible on an epistemological level; therefore, the two kinds of methods are incompatible. HOWE 1998, argues that a principle implicit in the incompatibilist's argument ‘that abstract paradigms should determine research methods in a one-way fashion—is untenable’. That paradigms must demonstrate their worth in terms of how they inform, and are informed by, research methods that are successfully employed. Given such a two-way relationship between methods and paradigms, paradigms are evaluated in terms of how well they square with the demands of research practice and incompatibilism vanishes. == References == Onwuegbuzie, Anthony J.; Leech, Nancy L. (2005). "Taking the "Q"


id: indicator-statistics-20260505-0
file: data/en.wikipedia.org/wiki/Indicator_(statistics)-0.md
category: reference
title: Indicator (statistics)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Indicator_(statistics)
date_saved: 2026-05-05T10:02:26.271833+00:00
instance: kb-cron
parent: indicator-statistics-20260505-0
summary:
In statistics and research design, an indicator is an observed value of a variable, or in other words "a sign of a presence or absence of the concept being studied". Just like each color indicates in a traffic lights the change in the movement. For example, if a variable is religiosity, and a unit of analysis is an individual, then that one of potentially more numerous indicators of that individual's religiosity would be whether they attend religious services; others - how often, or whether they donate money to religious organizations. Numerous indicators can be aggregated into an index. The complexity of biological systems makes evaluating them a challenge. Bioindicators, such as indicator bacteria, are ecological indicators, sometimes requiring further consideration of environmental indicators. In public health study, one relies on health indicators. In a given locality, community indicators inform planners, while the design quality indicator can be the basis of building permits. Assessment of social conditions relies on sustainability indicators or the genuine progress indicator. Standard measurements are given in the OECD Main Economic Indicators. A famous popular science individual psychological assessment is the Myers–Briggs Type Indicator. == References ==


id: infoq-20260505-0
file: data/en.wikipedia.org/wiki/InfoQ-0.md
category: reference
title: InfoQ
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/InfoQ
date_saved: 2026-05-05T10:02:27.431143+00:00
instance: kb-cron
parent: infoq-20260505-0
summary:
Information quality (InfoQ) is the extent to which a data set can help achieve a specific scientific or practical goal when it is used with a particular empirical analysis method. == Definition == InfoQ is often expressed as InfoQ = U(X,f|g), where X is the data, f is the analysis method, g is the goal, and U is the utility function. In simpler terms, it describes how useful a given set of data is for answering a particular question with a particular method. InfoQ is related to both data quality and analysis quality, but it is not the same as either one; it depends on the quality of the data, the suitability of the analysis, and how well the data, method, and goal fit together. InfoQ has been applied in fields including healthcare, customer surveys, data science programmes, advanced manufacturing, and Bayesian network applications. Kenett and Shmueli (2014) proposed eight dimensions to help assess InfoQ and various methods for increasing InfoQ: data resolution, data structure, data integration, temporal relevance, chronology of data and goal, generalization, operationalization, and communication. == References ==


id: intermediated-research-20260505-0
file: data/en.wikipedia.org/wiki/Intermediated_research-0.md
category: reference
title: Intermediated research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Intermediated_research
date_saved: 2026-05-05T10:02:28.622602+00:00
instance: kb-cron
parent: intermediated-research-20260505-0
summary:
In finance, intermediated research is a type of fundamental analysis or investment analysis of a business to establish its value for investors that attempts to avoid commercial pressure or influence. Many banks and brokers provide research to the investment community, however this form of research suffers from a real or perceived lack of objectivity. For example, this research may be subject to influence from within a bank from, say, investment bankers keen to win company’s IPO mandate. An alternative form is known as independent research or alternative research, this is research that is not provided by a bank or broker. However, someone has to fund the costs of conducting the research, and when the funder is the company being researched, this form of independent research is termed “sponsored” or “company-paid” research. Unfortunately, with the subject company paying directly for these services, this form of research suffers from a real or perceived lack of objectivity, which reduces its value to investors and hence to the companies themselves. Intermediated research improves significantly upon the sponsored research model, by introducing important safeguards into the commercial and research process framework. The key structure is that the company has no choice in its allocation to


id: literature-review-20260505-0
file: data/en.wikipedia.org/wiki/Literature_review-0.md
category: reference
title: Literature review
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Literature_review
date_saved: 2026-05-05T10:02:29.835558+00:00
instance: kb-cron
parent: literature-review-20260505-0
summary:
A literature review is an overview of previously published works on a particular topic. The term can refer to a full scholarly paper or a section of a scholarly work such as books or articles. Either way, a literature review provides the researcher/author and the audiences with general information of an existing knowledge of a particular topic. A good literature review has a proper research question, a proper theoretical framework, and/or a chosen research method. It serves to situate the current study within the body of the relevant literature and provides context for the reader. In such cases, the review usually precedes the methodology and results sections of the work. Producing a literature review is often part of a graduate and post-graduate requirement, included in the preparation of a thesis, dissertation, or a journal article. Literature reviews are also common in a research proposal or prospectus (the document approved before a student formally begins a dissertation or thesis). A literature review can be a type of a review article. In this sense, it is a scholarly paper that presents the current knowledge including substantive findings as well as theoretical and methodological contributions to a particular topic. Literature reviews are secondary


id: longitudinal-study-20260505-0
file: data/en.wikipedia.org/wiki/Longitudinal_study-0.md
category: reference
title: Longitudinal study
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Longitudinal_study
date_saved: 2026-05-05T10:02:31.046324+00:00
instance: kb-cron
parent: longitudinal-study-20260505-0
summary:
A longitudinal study (or longitudinal survey, or panel study) is a research design that involves repeated observations of the same variables (e.g., people) over long periods of time (i.e., uses longitudinal data). It is often a type of observational study, although it can also be structured as longitudinal randomized experiment. Longitudinal studies are often used in social-personality and clinical psychology, to study rapid fluctuations in behaviors, thoughts, and emotions from moment to moment or day to day; in developmental psychology, to study developmental trends across the life span; and in sociology, to study life events throughout lifetimes or generations; and in consumer research and political polling to study consumer trends. The reason for this is that, unlike cross-sectional studies, in which different individuals with the same characteristics are compared, longitudinal studies track the same people, and so the differences observed in those people are less likely to be the result of cultural differences across generations, that is, the cohort effect. Longitudinal studies thus make observing changes more accurate and are applied in various other fields. In medicine, the design is used to uncover predictors of certain diseases. In advertising, the design is used to identify the changes that advertising has


id: massive-online-open-research-20260505-0
file: data/en.wikipedia.org/wiki/Massive_online_open_research-0.md
category: reference
title: Massive online open research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Massive_online_open_research
date_saved: 2026-05-05T10:02:32.161019+00:00
instance: kb-cron
parent: massive-online-open-research-20260505-0
summary:
Massive online open research (MOOR) is an online research and development (R&D) open access platform or higher education study program aiming at unlimited participation via the internet. It may be used to create, on a very large participative scale, a new discovery, development or creation which will be allegedly accompanied by a peer-review publication. == As a higher education online research program == In September 2013, The University of California in San Diego bioinformatics department, proposed a massive online open course which would feature "an opportunity (for students) to work on specific research projects under the leadership of prominent bioinformatics scientists". == As an online internet platform == Several internet platforms have shown their interest in bridging prominent science, technology, engineering and mathematics (i.e., STEM fields) researchers with students, as means to accelerate STEM discoveries and education. The internet social network Research Gate has unveiled that multiple discoveries and advancements in science have been made collaboratively in an open access scheme since its creation, essentially serving as a MOOR platform. The University of Amsterdam has been developing an online tool for massive online open research since February 2014. This tool will primarily focus on collaborative (qualitative) data analysis. == See


id: megastudy-20260505-0
file: data/en.wikipedia.org/wiki/Megastudy-0.md
category: reference
title: Megastudy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Megastudy
date_saved: 2026-05-05T10:02:33.313578+00:00
instance: kb-cron
parent: megastudy-20260505-0
summary:
A megastudy or mega-study is a research study in which a large number of different treatments or interventions are tested at the same time, on the same sample or similar samples, using a common outcome measure, and using the same experimental protocol. == Megastudy examples == Exercise encouragement Vaccination nudges Strengthening of democratic attitudes Interventions against climate change == Many-lab studies == The megastudy technique can be combined with the many-labs approach, so that teams of researchers from across the planet conduct the same experiment locally. == Megastudy criticisms == Statistical power: While the overall megastudy sample size may be large, the sample size per intervention may be relatively small, leading to underpowered designs with wide confidence intervals. As a result, while interventions may be comparable, their relative ranking by outcome measure may be noisy. Increased sample size can help address this issue. Lack of theory: The megastudy technique may be considered a form of "fishing expedition" for what interventions have strongest effect on the outcome measure, without much theory building. == References ==


id: methods-in-molecular-biology-20260505-0
file: data/en.wikipedia.org/wiki/Methods_in_Molecular_Biology-0.md
category: reference
title: Methods in Molecular Biology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Methods_in_Molecular_Biology
date_saved: 2026-05-05T10:02:34.484979+00:00
instance: kb-cron
parent: methods-in-molecular-biology-20260505-0
summary:
Methods in Molecular Biology is a book series published by Humana Press (an imprint of Springer Science+Business Media) that covers molecular biology research methods and protocols. The book series was introduced by series editor John M. Walker in 1983 and provides step-by-step instructions for carrying out experiments in a research lab. As of January 2020, more than 2000 volumes (2737 as of 15-August-2023) had been published in the series. The protocols are also available online in SpringerLink, and were previously in Springer Protocols. Each protocol opens with an introductory overview and a list of the materials and reagents needed to complete the experiment. Every protocol is followed by a detailed procedure that is supported with a notes section offering tips and "tricks of the trade" as well as troubleshooting advice. == See also == Biological Procedures Online == References == == External links == Official website


id: microphysiometry-20260505-0
file: data/en.wikipedia.org/wiki/Microphysiometry-0.md
category: reference
title: Microphysiometry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Microphysiometry
date_saved: 2026-05-05T10:02:35.668394+00:00
instance: kb-cron
parent: microphysiometry-20260505-0
summary:
Microphysiometry is the in vitro micro-measurement of the functions and activities of life or of living matter (as organs, tissues, or cells) and of the physical and chemical phenomena involved on a very small micrometer (μm) scale. The term microphysiometry emerged in the scientific literature at the end of the 1980s. The primary parameters assessed in microphysiometry comprise pH and the concentration of dissolved oxygen, glucose, and lactic acid, with an emphasis on the first two. Measuring these parameters experimentally in combination with a fluidic system for cell culture maintenance and a defined application of drugs or toxins provides three quantitative output parameters: extracellular acidification rates (EAR), oxygen uptake rates (OUR), and rates of glucose consumption or lactate release that characterize the metabolic situation. Due to the label-free nature of sensor-based measurements, dynamic monitoring of cells or tissues for several days or even longer is feasible. On an extended timescale, a dynamic analysis of a cell's metabolic response to an experimental treatment can distinguish acute effects (e.g., one hour after a treatment), early effects (e.g., at 24 hours), and delayed, chronic responses (e.g., at 96 hours). As stated by Alajoki et al., "The concept is that it is possible to


id: model-for-assessment-of-telemedicine-20260505-0
file: data/en.wikipedia.org/wiki/Model_for_assessment_of_telemedicine-0.md
category: reference
title: Model for assessment of telemedicine
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Model_for_assessment_of_telemedicine
date_saved: 2026-05-05T10:02:36.828432+00:00
instance: kb-cron
parent: model-for-assessment-of-telemedicine-20260505-0
summary:
Model for assessment of telemedicine (MAST) is a framework for assessment of the value of telemedicine. == Description == Telemedicine services may have many different types of outcomes and can be studied in many ways. In order for those who develop new telemedicine services to produce the information that healthcare managers need for making decisions on investment in telemedicine, a model for assessment of telemedicine (MAST) was developed. This work was done in 2010 through stakeholder workshops and on the basis of a systematic literature review. If the goal of evaluating telemedicine applications is to assess their effectiveness and impact on the quality of care, and to provide a foundation for decision-making, then according to MAST, the appropriate assessment framework is a multidisciplinary process. This process involves summarizing and evaluating information concerning medical, social, economic, and ethical considerations related to telemedicine in a systematic, impartial, and rigorous manner. This statement is based on the definition of Health technology assessment (HTA) in the EUnetHTA project. Key concepts are "multidisciplinary" and "systematic, unbiased and robust". The first concept implies that the assessments should include all important outcomes of the applications for patients, clinicians, healthcare institutions and society in general. The others imply


id: motion-analysis-20260505-0
file: data/en.wikipedia.org/wiki/Motion_analysis-0.md
category: reference
title: Motion analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Motion_analysis
date_saved: 2026-05-05T10:02:38.023893+00:00
instance: kb-cron
parent: motion-analysis-20260505-0
summary:
Motion analysis is used in computer vision, image processing, high-speed photography and machine vision that studies methods and applications in which two or more consecutive images from an image sequences, e.g., produced by a video camera or high-speed camera, are processed to produce information based on the apparent motion in the images. In some applications, the camera is fixed relative to the scene and objects are moving around in the scene, in some applications the scene is more or less fixed and the camera is moving, and in some cases both the camera and the scene are moving. The motion analysis processing can in the simplest case be to detect motion, i.e., find the points in the image where something is moving. More complex types of processing can be to track a specific object in the image over time, to group points that belong to the same rigid object that is moving in the scene, or to determine the magnitude and direction of the motion of every point in the image. The information that is produced is often related to a specific image in the sequence, corresponding to a specific time-point, but then depends also on the neighboring images. This


id: motion-analysis-20260505-1
file: data/en.wikipedia.org/wiki/Motion_analysis-1.md
category: reference
title: Motion analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Motion_analysis
date_saved: 2026-05-05T10:02:38.023893+00:00
instance: kb-cron
parent: motion-analysis-20260505-0
summary:
=== Human motion analysis === In the areas of medicine, sports, video surveillance, physical therapy, and kinesiology, human motion analysis has become an investigative and diagnostic tool. See the section on motion capture for more detail on the technologies. Human motion analysis can be divided into three categories: human activity recognition, human motion tracking, and analysis of body and body part movement. Human activity recognition is most commonly used for video surveillance, specifically automatic motion monitoring for security purposes. Most efforts in this area rely on state-space approaches, in which sequences of static postures are statistically analyzed and compared to modeled movements. Template-matching is an alternative method whereby static shape patterns are compared to pre-existing prototypes. Human motion tracking can be performed in two or three dimensions. Depending on the complexity of analysis, representations of the human body range from basic stick figures to volumetric models. Tracking relies on the correspondence of image features between consecutive frames of video, taking into consideration information such as position, color, shape, and texture. Edge detection can be performed by comparing the color and/or contrast of adjacent pixels, looking specifically for discontinuities or rapid changes. Three-dimensional tracking is fundamentally identical to two-dimensional tracking, with


id: multimethodology-20260505-0
file: data/en.wikipedia.org/wiki/Multimethodology-0.md
category: reference
title: Multimethodology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Multimethodology
date_saved: 2026-05-05T10:02:39.234877+00:00
instance: kb-cron
parent: multimethodology-20260505-0
summary:
Multimethodology or multimethod research includes the use of more than one method of data collection or research in a research study or set of related studies. Mixed methods research is more specific in that it includes the mixing of qualitative and quantitative data, methods, methodologies, and/or paradigms in a research study or set of related studies. One could argue that mixed methods research is a special case of multimethod research. Another applicable, but less often used label, for multi or mixed research is methodological pluralism. All of these approaches to professional and academic research emphasize that monomethod research can be improved through the use of multiple data sources, methods, research methodologies, perspectives, standpoints, and paradigms. The term multimethodology was used starting in the 1980s and in the 1989 book Multimethod Research: A Synthesis of Styles by John Brewer and Albert Hunter. During the 1990s and currently, the term mixed methods research has become more popular for this research movement in the behavioral, social, business, and health sciences. This pluralistic research approach has been gaining in popularity since the 1980s. == Multi and mixed methods research designs == There are four broad classes of research studies that are currently being labeled


id: multimethodology-20260505-1
file: data/en.wikipedia.org/wiki/Multimethodology-1.md
category: reference
title: Multimethodology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Multimethodology
date_saved: 2026-05-05T10:02:39.234877+00:00
instance: kb-cron
parent: multimethodology-20260505-0
summary:
=== History of Pragmatism in Multi/Mixed Methods Research === Developed as a philosophical method to solve problems towards the end of the nineteenth century, pragmatism is attributed to the work of philosopher Charles Sanders Peirce. For Peirce, research is conducted and interpreted from the eye of the beholder, as a practical approach to investigating social affairs. He sees science as a communal affair leading to single truths that are arrived at from multiple perspectives. For Peirce, the research conclusions are not as important as how these conclusions are reached. Focus is on answering the research question while allowing the methods to emerge in the process. Peirce pragmatism and its approach to research support qualitatively driven mixed methods studies. John Dewey extends both, "Peirce pragmatic method and (William) James' radical empiricism (and approach to experience) by application to social and political problems." His philosophical pragmatism takes an interdisciplinary approach, where the divide between quantitative and qualitative research represents an obstacle to solving a problem. In Dewey's pragmatism, success is measured by the outcome, where the outcome is the reason to engage in research. Live experiences constitute reality, were individual lived experiences form a continuum by the interaction of subjective (internal) and


id: multimethodology-20260505-2
file: data/en.wikipedia.org/wiki/Multimethodology-2.md
category: reference
title: Multimethodology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Multimethodology
date_saved: 2026-05-05T10:02:39.234877+00:00
instance: kb-cron
parent: multimethodology-20260505-0
summary:
== In contrast to quantitative and qualitative methodologies == One major similarity between mixed methodologies and qualitative and quantitative taken separately is that researchers need to maintain focus on the original purpose behind their methodological choices. A major difference between the two, however, is the way some authors differentiate the two, proposing that there is logic inherent in one that is different from the other. Creswell (2009) points out that in a quantitative study the researcher starts with a problem statement, moving on to the hypothesis and null hypothesis, through the instrumentation into a discussion of data collection, population, and data analysis. Creswell proposes that for a qualitative study the flow of logic begins with the purpose for the study, moves through the research questions discussed as data collected from a smaller group and then voices how they will be analysed. A research strategy is a procedure for achieving a particular intermediary research objective — such as sampling, data collection, or data analysis. We may therefore speak of sampling strategies or data analysis strategies. The use of multiple strategies to enhance construct validity (a form of methodological triangulation) is now routinely advocated by methodologists. In short, mixing or integrating research


id: multimodal-anthropology-20260505-0
file: data/en.wikipedia.org/wiki/Multimodal_anthropology-0.md
category: reference
title: Multimodal anthropology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Multimodal_anthropology
date_saved: 2026-05-05T10:02:40.406904+00:00
instance: kb-cron
parent: multimodal-anthropology-20260505-0
summary:
Multimodal anthropology is an emerging subfield of social cultural anthropology that encompasses anthropological research and knowledge production across multiple traditional and new media platforms and practices including film, video, photography, theatre, design, podcast, mobile apps, interactive games, web-based social networking, immersive 360 video and augmented reality. As characterized in American Anthropologist, multimodal anthropology is an "anthropology that works across multiple media, but one that also engages in public anthropology and collaborative anthropology through a field of differentially linked media platforms" (Collins, Durington & Gill). A multimodal approach also encourages anthropologists to reconsider the ways in which they conduct their research, to pay close attention to the role various media technologies and digital devices plays in the lives of their interlocutors, and how they these technologies redefine what fieldwork looks like. Scholars Collins, Durington, and Gill call it "anthropology that works across multiple media." It's not just about doing research alone; it's also about working with others and looking at how we do research in new ways, as well as an 'embodied practice', according to Varvantakis and Nolas. Multimodal anthropology has been growing since the early days of anthropology, changing along with new technology. It's not just about pictures anymore; now


id: multiplex-assay-20260505-0
file: data/en.wikipedia.org/wiki/Multiplex_(assay)-0.md
category: reference
title: Multiplex (assay)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Multiplex_(assay)
date_saved: 2026-05-05T10:02:41.610505+00:00
instance: kb-cron
parent: multiplex-assay-20260505-0
summary:
In the biological sciences, a multiplex assay is a type of immunoassay that uses magnetic beads to simultaneously measure multiple analytes in a single experiment. A multiplex assay is a derivative of an ELISA using beads for binding the capture antibody. Multiplex assays are still more common in research than in clinical settings. In a multiplex assay, microspheres of designated colors are coated with antibodies of defined binding specificities. The results can be read by flow cytometry because the beads are distinguishable by fluorescent signature. The number of analytes measured is determined by the number of different bead colors. Multiplex assays within a given application area or class of technology can be further stratified based on how many analytes can be measured per assay, where "multiplex" refers to those with the highest number of analyte measurements per assay (up to millions) and "low-plex" or "mid-plex" refers to procedures that process fewer (10s to 1000s), though there are no formal guidelines for calling a procedure multi-, mid-, or low-plex based on number of analytes measured. Single-analyte assays or low-to-mid-plex procedures typically predate the rise of their multiplex versions, which often require specialized technologies or miniaturization to achieve a higher degree of


id: network-based-diffusion-analysis-20260505-0
file: data/en.wikipedia.org/wiki/Network-based_diffusion_analysis-0.md
category: reference
title: Network-based diffusion analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Network-based_diffusion_analysis
date_saved: 2026-05-05T10:02:42.840541+00:00
instance: kb-cron
parent: network-based-diffusion-analysis-20260505-0
summary:
Network-based diffusion analysis (NBDA) is a statistical tool to detect and quantify social transmission of information or a behaviour in social networks (SNA, etc.). NBDA assumes that social transmission of a behavior follows the social network of associations or interactions among individuals, since individuals who spend a lot of time together, or who interact more have more opportunity to learn from each other. Therefore, NBDA infers social transmission if the spread of a novel behavior follows the social network of a population. NBDA thus allows the study of social learning to be linked to animal behavior research that uses social network analysis. NBDA was introduced by Franz & Nunn and further developed by Hoppitt, Boogert, & Laland. An R package for performing Bayesian NBDA, STbayes, was published by Chimento & Hoppitt in 2025. == Implementation == NBDA requires prior knowledge about the underlying social network of a population. In an observational study, the order (or timing) at which individuals in the population acquire a behaviour or information is recorded. NBDA then tests whether the spread of information or behaviour is explained by the previously determined network or not. Because more closely associated individuals are more likely to interact with each


id: open-label-trial-20260505-0
file: data/en.wikipedia.org/wiki/Open-label_trial-0.md
category: reference
title: Open-label trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Open-label_trial
date_saved: 2026-05-05T10:02:44.071326+00:00
instance: kb-cron
parent: open-label-trial-20260505-0
summary:
An open-label trial, or open trial, is a type of clinical trial in which information is not withheld from trial participants. In particular, both the researchers and participants know which treatment is being administered. This contrasts with a double-blinded trial, where information is withheld both from the researchers and the participants to reduce bias. Open-label trials may be appropriate for comparing two similar treatments to determine which is most effective, such as a comparison of different prescription anticoagulants, or possible relief from symptoms of some disorders when a placebo is given. An open-label trial may still be randomized. Open-label trials may also be uncontrolled (without a placebo group), with all participants receiving the same treatment. This would be a single-arm study design. == References ==


id: parallel-study-20260505-0
file: data/en.wikipedia.org/wiki/Parallel_study-0.md
category: reference
title: Parallel study
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Parallel_study
date_saved: 2026-05-05T10:02:45.211284+00:00
instance: kb-cron
parent: parallel-study-20260505-0
summary:
A parallel study is a type of clinical study where two groups of treatments, A and B, are given so that one group receives only A while another group receives only B. Other names for this type of study include "between patient" and "non-crossover". This is unlike a crossover study where at first one group receives treatment A and later followed by treatment B while the other group receives treatment B followed by treatment A. There are, however, certain characteristics that allow for differentiation between these two types of trials. For example, a parallel study would be more appropriate if any concerns about carryover effects were present. This type of study might also be more beneficial if the disease or disorder being studied has a likely chance of progression during the time in which the study takes place. One significant issue with parallel studies, though, is the concept of intra subject variability, which is defined as variability in response occurring within the same patient. The two treatment groups in a parallel study can either consist of two completely separate treatments (i.e. different drugs), or simply different doses of a common drug. One major aspect of a parallel study is randomization


id: parataxonomy-20260505-0
file: data/en.wikipedia.org/wiki/Parataxonomy-0.md
category: reference
title: Parataxonomy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Parataxonomy
date_saved: 2026-05-05T10:02:46.406435+00:00
instance: kb-cron
parent: parataxonomy-20260505-0
summary:
Parataxonomy is a system of labor division for use in biodiversity research, in which the rough sorting tasks of specimen collection, field identification, documentation and preservation are conducted by primarily local, less specialized individuals, thereby alleviating the workload for the "alpha" or "master" taxonomist. Parataxonomy may be used to improve taxonomic efficiency by enabling more expert taxonomists to restrict their activity to the tasks that require their specialist knowledge and skills, which has the potential to expedite the rate at which new taxa may be described and existing taxa may be sorted and discussed. Parataxonomists generally work in the field, sorting collected samples into recognizable taxonomic units (RTUs) based on easily recognized features. The process can be used alone for rapid assessment of biodiversity. Some researchers consider reliance on parataxonomist-generated data to be prone to error depending on the sample, the sorter and the group of organisms in question. Therefore, quantitative studies based on parataxonomic processes may be unreliable and is therefore controversial. The concepts of citizen science and parataxonomy are somewhat overlapping, with unclear distinctions between those employed to provide supplemental services to taxonomists and those who do so voluntarily, whether for personal enrichment or the altruistic desire to


id: participatory-action-research-20260505-0
file: data/en.wikipedia.org/wiki/Participatory_action_research-0.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
Participatory action research (PAR) is an approach to action research emphasizing participation and action by members of communities affected by that research. It seeks to understand the world by trying to change it, collaboratively and following reflection. PAR emphasizes collective inquiry and experimentation grounded in experience and social history. Within a PAR process, "communities of inquiry and action evolve and address questions and issues that are significant for those who participate as co-researchers". PAR contrasts with mainstream research methods, which emphasize controlled experimentaction, statistical analysis, and reproducibility of findings. PAR practitioners make a concerted effort to integrate three basic aspects of their work: participation (life in society and democracy), action (engagement with experience and history), and research (soundness in thought and the growth of knowledge). "Action unites, organically, with research" and collective processes of self-investigation. The way each component is actually understood and the relative emphasis it receives varies nonetheless from one PAR theory and practice to another. This means that PAR is not a monolithic body of ideas and methods but rather a pluralistic orientation to knowledge making and social change. == Overview == In the UK and North America the work of Kurt Lewin and the Tavistock Institute


id: participatory-action-research-20260505-1
file: data/en.wikipedia.org/wiki/Participatory_action_research-1.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
"Do not monopolise your knowledge nor impose arrogantly your techniques, but respect and combine your skills with the knowledge of the researched or grassroots communities, taking them as full partners and co-researchers. Do not trust elitist versions of history and science which respond to dominant interests, but be receptive to counter-narratives and try to recapture them. Do not depend solely on your culture to interpret facts, but recover local values, traits, beliefs, and arts for action by and with the research organisations. Do not impose your own ponderous scientific style for communicating results, but diffuse and share what you have learned together with the people, in a manner that is wholly understandable and even literary and pleasant, for science should not be necessarily a mystery nor a monopoly of experts and intellectuals." PAR can be thought of as a guiding paradigm to influence and democratize the creation of knowledge making, and ground it in real community needs and learning. Knowledge production controlled by elites can sometimes further oppress marginalized populations. PAR can be a way of overcoming the ineffectiveness and elitism of conventional schooling and science, and the negative effects of market forces and industry on the workplace, community life


id: participatory-action-research-20260505-2
file: data/en.wikipedia.org/wiki/Participatory_action_research-2.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
=== Organizational life === Action research in the workplace took its initial inspiration from Lewin's work on organizational development (and Dewey's emphasis on learning from experience). Lewin's seminal contribution involves a flexible, scientific approach to planned change that proceeds through a spiral of steps, each of which is composed of 'a circle of planning, action, and fact-finding about the result of the action', towards an organizational 'climate' of democratic leadership and responsible participation that promotes critical self-inquiry and collaborative work. These steps inform Lewin's work with basic skill training groups, T-groups where community leaders and group facilitators use feedback, problem solving, role play and cognitive aids (lectures, handouts, film) to gain insights into themselves, others and groups with a view to 'unfreezing' and changing their mindsets, attitudes and behaviours. Lewin's understanding of action-research coincides with key ideas and practices developed at the influential Tavistock Institute (created in 1947)) in the UK and National Training Laboratories (NTL) in the US. An important offshoot of Tavistock thinking and practise is the sociotechnical systems perspective on workplace dynamics, guided by the idea that greater productivity or efficiency does not hinge on improved technology alone. Improvements in organizational life call instead for the interaction


id: participatory-action-research-20260505-3
file: data/en.wikipedia.org/wiki/Participatory_action_research-3.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
=== Community development and sustainable livelihoods === PAR emerged in the postwar years as an important contribution to intervention and self-transformation within groups, organizations and communities. It has left a singular mark on the field of rural and community development, especially in the Global South. Tools and concepts for doing research with people, including "barefoot scientists" and grassroots "organic intellectuals" (see Gramsci), are now promoted and implemented by many international development agencies, researchers, consultants, civil society and local community organizations around the world. This has resulted in countless experiments in diagnostic assessment, scenario planning and project evaluation in areas ranging from fisheries and mining to forestry, plant breeding, agriculture, farming systems research and extension, watershed management, resource mapping, environmental conflict and natural resource management, land rights, appropriate technology, local economic development, communication, tourism, leadership for sustainability, biodiversity and climate change. This prolific literature includes the many insights and methodological creativity of participatory monitoring, participatory rural appraisal (PRA) and participatory learning and action (PLA) and all action-oriented studies of local, indigenous or traditional knowledge. On the whole, PAR applications in these fields are committed to problem solving and adaptation to nature at the household or community level, using friendly methods of


id: participatory-action-research-20260505-4
file: data/en.wikipedia.org/wiki/Participatory_action_research-4.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
=== Feminism and gender === Feminist research and women's development theory also contributed to rethinking the role of scholarship in challenging existing regimes of power, using qualitative and interpretive methods that emphasize subjectivity and self-inquiry rather than the quantitative approach of mainstream science. As did most research in the 1970s and 1980s, PAR remained androcentric. In 1987, Patricia Maguire critiqued this male-centered participatory research, arguing that "rarely have feminist and participatory action researchers acknowledged each other with mutually important contributions to the journey." Given that PAR aims to give equitable opportunity for diverse and marginalized voices to be heard, engaging gender minorities is an integral pillar in PAR's tenants. In addition to gender minorities, PAR must consider points of intersecting oppressions individuals may experience. After Maguire published Traveling Companions: Feminism, Teaching, And Action Research, PAR began to extend toward not only feminism, but also Intersectionality through Black Feminist Thought and Critical Race Theory (CRT). Today, applying an intersectional feminist lens to PAR is crucial to recognize the social categories, such as race, class, ability, gender, and sexuality, that construct individuals' power relations and lived experiences. PAR seeks to recognize the deeply complex condition of human living. Therefore, framing PAR's qualitative


id: participatory-action-research-20260505-5
file: data/en.wikipedia.org/wiki/Participatory_action_research-5.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
== Ethics == Given the often delicate power balances between researchers and participants in PAR, there have been calls for a code of ethics to guide the relationship between researchers and participants in a variety of PAR fields. Norms in research ethics involving humans include respect for the autonomy of individuals and groups to deliberate about a decision and act on it. This principle is usually expressed through the free, informed and ongoing consent of those participating in research (or those representing them in the case of persons lacking the capacity to decide). Another mainstream principle is the welfare of participants who should not be exposed to any unfavourable balance of benefits and risks with participation in research aimed at the advancement of knowledge, especially those that are serious and probable. Since privacy is a factor that contributes to people's welfare, confidentiality obtained through the collection and use of data that are anonymous (e.g. survey data) or anonymized tends to be the norm. Finally, the principle of justice—equal treatment and concern for fairness and equity—calls for measures of appropriate inclusion and mechanisms to address conflicts of interests. While the choice of appropriate norms of ethical conduct is rarely an either/or


id: participatory-action-research-20260505-6
file: data/en.wikipedia.org/wiki/Participatory_action_research-6.md
category: reference
title: Participatory action research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_action_research
date_saved: 2026-05-05T10:02:47.553680+00:00
instance: kb-cron
parent: participatory-action-research-20260505-0
summary:
== Challenges == PAR offers a long history of experimentation with evidence-based and people-based inquiry, a groundbreaking alternative to mainstream positive science. As with positivism, the approach creates many challenges as well as debates on what counts as participation, action and research. Differences in theoretical commitments (Lewinian, Habermasian, Freirean, psychoanalytic, feminist, etc.) and methodological inclinations (quantitative, qualitative, mixed) are numerous and profound. This is not necessarily a problem, given the pluralistic value system built into PAR. Ways to better answer questions pertaining to PAR's relationship with science and social history are nonetheless key to its future. One critical question concerns the problem-solving orientation of engaged inquiry—the rational means-ends focus of most PAR experiments as they affect organizational performance or material livelihoods, for instance. In the clinical perspective of French psychosociology, a pragmatic orientation to inquiry neglects forms of understanding and consciousness that are not strictly instrumental and rational. PAR must pay equal attention to the interconnections of self-awareness, the unconscious and life in society. Another issue, more widely debated, is scale—how to address broad-based systems of power and issues of complexity, especially those of another development on a global scale. How can PAR develop a macro-orientation to democratic dialogue and


id: participatory-design-20260505-0
file: data/en.wikipedia.org/wiki/Participatory_design-0.md
category: reference
title: Participatory design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_design
date_saved: 2026-05-05T10:02:48.714500+00:00
instance: kb-cron
parent: participatory-design-20260505-0
summary:
Participatory design (originally co-operative design or design participation, now often co-design and also co-creation) is an approach to design that attempts to involve a variety of stakeholders (e.g. employees, partners, customers, citizens, end users) in the design process to help ensure the result meets their needs and is usable. Participatory design is an approach which is focused on processes and procedures of design and is not a design style. The term is used in a variety of fields, e.g. software design, urban design, architecture, landscape architecture, product design, sustainability, graphic design, industrial design, planning, and health services development, as a way of creating environments that are more satisfactory and appropriate to their inhabitants' and users' practical, cultural, emotional and spiritual needs. It is also one approach to placemaking. Participatory design has been used in many settings and at various scales. For some, this approach has a political dimension of user empowerment and democratization. This inclusion of external parties in the design process does not excuse designers of their responsibilities. In their article "Participatory Design and Prototyping", Wendy Mackay and Michel Beaudouin-Lafon support this point by stating that "[a] common misconception about participatory design is that designers are expected to abdicate


id: participatory-design-20260505-1
file: data/en.wikipedia.org/wiki/Participatory_design-1.md
category: reference
title: Participatory design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_design
date_saved: 2026-05-05T10:02:48.714500+00:00
instance: kb-cron
parent: participatory-design-20260505-0
summary:
=== History in Scandinavia === In several Scandinavian countries, during the 1960s and 1970s, participatory design was rooted in work with trade unions; its ancestry also includes action research and sociotechnical design. Research projects on user participation in systems development date back to the 1970s. The so-called "collective resource approach" developed strategies and techniques for workers to influence the design and use of computer applications at the workplace: The Norwegian Iron and Metal Workers Union (NJMF) project took a first move from traditional research to working with people, directly changing the role of the union clubs in the project. The Scandinavian projects developed an action research approach, emphasizing active co-operation between researchers and workers of the organization to help improve the latter's work situation. While researchers got their results, the people whom they worked with were equally entitled to get something out of the project. The approach built on people's own experiences, providing for them resources to be able to act in their current situation. The view of organizations as fundamentally harmonious—according to which conflicts in an organization are regarded as pseudo-conflicts or "problems" dissolved by good analysis and increased communication—was rejected in favor of a view of organizations recognizing


id: participatory-design-20260505-2
file: data/en.wikipedia.org/wiki/Participatory_design-2.md
category: reference
title: Participatory design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_design
date_saved: 2026-05-05T10:02:48.714500+00:00
instance: kb-cron
parent: participatory-design-20260505-0
summary:
Public interest design is a design movement, extending to architecture, with the main aim of structuring design around the needs of the community. At the core of its application is participatory design. Through allowing individuals to have a say in the process of design of their own surrounding built environment, design can become proactive and tailored towards addressing wider social issues facing that community. Public interest design is meant to reshape conventional modern architectural practice. Instead of having each construction project solely meet the needs of the individual, public interest design addresses wider social issues at their core. This shift in architectural practice is a structural and systemic one, allowing design to serve communities responsibly. Solutions to social issues can be addressed in a long-term manner through such design, serving the public, and involving it directly in the process through participatory design. The built environment can become the very reason for social and community issues to arise if not executed properly and responsibly. Conventional architectural practice often does cause such problems since only the paying client has a say in the design process. Portland, Oregon City Repair Project was a form of participatory design involving the community co-designing problem areas


id: participatory-design-20260505-3
file: data/en.wikipedia.org/wiki/Participatory_design-3.md
category: reference
title: Participatory design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participatory_design
date_saved: 2026-05-05T10:02:48.714500+00:00
instance: kb-cron
parent: participatory-design-20260505-0
summary:
== Research methodology == Increasingly researchers are focusing on co-design as a way of doing research, and therefore are developing parts of its research methodology. For instance, in the field of generative co-design Vandekerckhove et al. have proposed a methodology to assemble a group of stakeholders to participate in generative co-design activities in the early innovation process. They propose first to sample a group of potential stakeholders through snowball sampling, afterwards interview these people and assess their knowledge and inference experience, lastly they propose to assemble a diverse group of stakeholders according to their knowledge and inference experience. Though not completely synonymous, research methods of Participatory Design can be defined under Participatory Research (PR): a term for research designs and frameworks using direct collaboration with those affected by the studied issue. More specifically, Participatory Design has evolved from Community-Based Research and Participatory Action Research (PAR). PAR is a qualitative research methodology involving: "three types of change, including critical consciousness development of researchers and participants, improvement of lives of those participating in research, and transformation of societal 'decolonizing' research methods with the power of healing and social justice". Participatory Action Research (PAR) is a subset of Community-Based Research aimed explicitly at


id: patient-and-public-involvement-20260505-0
file: data/en.wikipedia.org/wiki/Patient_and_public_involvement-0.md
category: reference
title: Patient and public involvement
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Patient_and_public_involvement
date_saved: 2026-05-05T10:02:49.972651+00:00
instance: kb-cron
parent: patient-and-public-involvement-20260505-0
summary:
Public involvement (or public and patient involvement, PPI) in medical research refers to the practice where people with health conditions (patients), carers and members of the public work together with researchers and influence what is researched and how. Involvement is not the same as participation which means taking part in research, for example taking a drug in a clinical trial. == Definition == Public involvement in medical research can be defined as research being carried out "with" or "by" members of the public rather than "to", "about" or "for" them. Through PPI patients, carers and people with lived experience work alongside researchers to influence and contribute to how research is designed and conducted. Members of the public involved in research are frequently referred to as public members or public contributors. === Terminology === Researchers and others use different terms to describe how they interact with the public, and this can vary across organisations and countries. The terms involvement, engagement and participation are sometimes used interchangeably. The National Institute for Health and Care Research (NIHR) uses the term public partnerships to encompass the components of involvement, engagement and participation. It can be summarised as "a term to collectively describe ways in


id: patient-and-public-involvement-20260505-1
file: data/en.wikipedia.org/wiki/Patient_and_public_involvement-1.md
category: reference
title: Patient and public involvement
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Patient_and_public_involvement
date_saved: 2026-05-05T10:02:49.972651+00:00
instance: kb-cron
parent: patient-and-public-involvement-20260505-0
summary:
Identifying and prioritising research. People with lived experience help to identify the right topics to ensure that the research is looking at what matters to them. Commissioning research. Involving members of the public in deciding which research proposals should get funding. Public members can also continue monitoring the research projects that get funded. Designing research. Public members help designing the research to make sure it is feasible, ethical and relevant. This happens usually before applying for funding. Managing research. Public involvement in the steering group or managing committee that oversees the research. Undertaking research. Members of the public help carrying out the research. This can include, for example, gathering evidence, reviewing literature, conducting interviews and focus groups, and analysing the results. Disseminating (sharing) research. Public members help sharing the findings of research. They can be consulted on the ways of dissemination, help summarising the research in plain language, work on accessibility issues. Implementing research. Public members influencing how the result is taken into practice and making sure it leads to action. Public involvement can be short-term and task-based or long-term across a research project or an institutional programme. == Barriers and issues == There are a wide range of challenges


id: patient-and-public-involvement-20260505-2
file: data/en.wikipedia.org/wiki/Patient_and_public_involvement-2.md
category: reference
title: Patient and public involvement
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Patient_and_public_involvement
date_saved: 2026-05-05T10:02:49.972651+00:00
instance: kb-cron
parent: patient-and-public-involvement-20260505-0
summary:
== Diversity and inclusion == In order for research to be relevant for all, the PPI process needs to include members of the public from diverse and inclusive groups. A 2021 survey highlights that the majority of public contributors to NIHR research were predominantly female (57%), 61 years of age and over, white and heterosexual. The Health Research Authority found that people from ethnic and lower socioeconomic groups felt less confident about being treated in a dignified and respectful way in research in comparison to white and higher socioeconomic individuals. Black and minority ethnic (BME) involvement in research has widespread support, however it tends to be limited to certain phases of the research cycle and particular ethnicities. === Frameworks for diversity === The Race Equality Framework (REF) was produced as a self assessment tool aiming to help organisations improve racial equity in health and care research. It was co-produced by the Race Equality Public Action Group (REPAG). Similar frameworks exist for research participants, for example, the INCLUDE ethnicity framework and the National Health Service (NHS) guidance for increasing diversity in research participation. == History == The development of patient and public involvement in research was influenced by grassroots social movements,


id: periscop-20260505-0
file: data/en.wikipedia.org/wiki/PERISCOP-0.md
category: reference
title: PERISCOP
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/PERISCOP
date_saved: 2026-05-05T10:02:51.163872+00:00
instance: kb-cron
parent: periscop-20260505-0
summary:
The PERISCOP is a pressurized recovery device designed for retrieving deep-sea marine life at depths exceeding 2,000 metres. The device was designed by Bruce Shillito and Gerard Hamel at the Universite Pierre et Marie Curie. The name is an acronym for the French phrase Projet d’Enceinte de Remontée Isobare Servant la Capture d’Organismes Profonds ("Enclosure project for isobaric ascent serving to capture deep organisms"). == History == The PERISCOP is a unique pressurized recovery device that contains three chambers – one for capture, one for recovery under exterior pressure, and one for transfer to the laboratory while maintaining pressure. Previous recovery devices used one chamber for all purposes. An arm designed to capture samples by force of suction is attached to the device. During ascent, pressure is maintained within the chamber by use of pressurized water. Upon surfacing, samples can be observed, filmed, and/or photographed through transparent view ports in the device. Due to fluctuations in atmospheric pressure and temperature recorded pressures during ascent and at the surface may ranged from 74%-111% of the natural pressure at sea depth. The device set a record for the deepest live-fish capture under pressure when it captured a Pachycara at 2,300 m. The


id: pooled-analysis-20260505-0
file: data/en.wikipedia.org/wiki/Pooled_analysis-0.md
category: reference
title: Pooled analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pooled_analysis
date_saved: 2026-05-05T10:02:52.330665+00:00
instance: kb-cron
parent: pooled-analysis-20260505-0
summary:
A pooled analysis is a statistical technique for combining the results of multiple epidemiological studies. It is one of three types of literature reviews frequently used in epidemiology, along with meta-analysis and traditional narrative reviews. Pooled analyses may be either retrospective or prospective. It is often used when the results of individual studies do not allow for a firm conclusion to be drawn. Unlike meta-analyses, pooled analyses can only be conducted if the included studies used the same study design and statistical models, and if their respective populations were homogeneous. If individual-level data from the included studies is available, the result of a pooled analysis can be considered more reliable. == References ==


id: postmortem-studies-20260505-0
file: data/en.wikipedia.org/wiki/Postmortem_studies-0.md
category: reference
title: Postmortem studies
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Postmortem_studies
date_saved: 2026-05-05T10:02:53.502702+00:00
instance: kb-cron
parent: postmortem-studies-20260505-0
summary:
Postmortem studies are a type of neurobiological research, which provides information to researchers and individuals who will have to make medical decisions in the future. Postmortem researchers conduct a longitudinal study of the brain of an individual, who has some sort of phenomenological condition (i.e. cannot speak, trouble moving left side of body, Alzheimer's, etc.) that is examined after death. Researchers look at certain lesions in the brain that could have an influence on cognitive or motor functions. These irregularities, damage, or other cerebral anomalies observed in the brain are attributed to an individual's pathophysiology and their environmental surroundings. Postmortem studies provide a unique opportunity for researchers to study different brain attributes that would be unable to be studied on a living person. Postmortem studies allow researchers to determine causes and cure for certain diseases and functions. It is critical for researchers to develop hypotheses, in order to discover the characteristics that are meaningful to a particular disorder. The results that the researcher discovers from the study will help the researcher trace the location in the brain to specific behaviors. When tissue from a postmortem study is obtained it is imperative that the researcher ensures the quality is adequate to


id: pragmatic-validity-20260505-0
file: data/en.wikipedia.org/wiki/Pragmatic_validity-0.md
category: reference
title: Pragmatic validity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pragmatic_validity
date_saved: 2026-05-05T10:02:54.708020+00:00
instance: kb-cron
parent: pragmatic-validity-20260505-0
summary:
Pragmatic validity in research looks to a different paradigms from more traditional, (post)positivistic research approaches. It tries to ameliorate problems associated with the rigour-relevance debate, and is applicable in all kinds of research streams. Simply put, pragmatic validity looks at research from a prescriptive-driven perspective. Solutions to problems that actually occur in the complex and highly multivariate field of practice are developed in a way that, while valid for a specific situation, need to be adjusted according to the context in which they are to be applied. The term "validity" is often seen as a sort catch-all for the question whether the knowledge claims resulting from research are warranted. The confusion might arise from the mingling of the terms 'internal validity' and 'external validity', where the former refers to proof of a causal link between a treatment and effect, and the latter is concerned with generalizability. (In this discussion I maintain the term 'generalizability' rather than external validity mainly to avoid any possible confusion between the two terms.) During this discussion I consider that validity is reflected in the question, "did we measure the right thing?", or, in other words, can the researcher prove that the effect he observed was


id: pragmatic-validity-20260505-1
file: data/en.wikipedia.org/wiki/Pragmatic_validity-1.md
category: reference
title: Pragmatic validity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pragmatic_validity
date_saved: 2026-05-05T10:02:54.708020+00:00
instance: kb-cron
parent: pragmatic-validity-20260505-0
summary:
Thus, Cook (1983) actually questions the validity of causal explanations generated in a context-free setting (the goal of positivistic, explanatory research). Causal relationships in pragmatic research are looked at somewhat differently, which is apparent in the wording alone. A statement about a causal relationship in positivistic research is something like the following; if you perform action x to subject y, then z happens. This assumes that the confounding variables have been ruled out, and the statement is always true, regardless of the situation (internally and externally valid). What I want to do now is use the concept of 'technological rules' in order to illustrate how causality is shown in prescriptive. In pragmatic science, the goal is to develop knowledge that can be used to improve a situation. This we can call prescriptive knowledge. Prescriptive knowledge, according to van Aken (2004, 2004b, 2005) can take the form of a technological rule. A technological rule is "... a chunk of general knowledge linking an intervention or artifact with an expected outcome or performance in a certain field of application" (van Aken, 2005: p23). This rule can be formulated much the same way as my earlier example of a causal statement; 'if you


id: qualitative-research-20260505-0
file: data/en.wikipedia.org/wiki/Qualitative_research-0.md
category: reference
title: Qualitative research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qualitative_research
date_saved: 2026-05-05T10:02:55.894451+00:00
instance: kb-cron
parent: qualitative-research-20260505-0
summary:
Qualitative research is a type of research that aims to gather and analyse non-numerical (descriptive) data in order to gain an understanding of individuals' social reality, including understanding their attitudes, beliefs, and motivation. This type of research typically involves in-depth interviews, focus groups, or field observations in order to collect data that is rich in detail and context. Qualitative research is often used to explore complex phenomena or to gain insight into people's experiences and perspectives on a particular topic. It is particularly useful when researchers want to understand the meaning that people attach to their experiences or when they want to uncover the underlying reasons for people's behavior. Qualitative methods include ethnography, grounded theory, discourse analysis, and interpretative phenomenological analysis. Qualitative research methods have been used in sociology, anthropology, political science, psychology, communication studies, social work, folklore, educational research, information science and software engineering research. == Background == Qualitative research has been informed by several strands of philosophical thought and examines aspects of human life, including culture, expression, beliefs, morality, life stress, and imagination. Contemporary qualitative research has been influenced by a number of branches of philosophy, for example, positivism, postpositivism, critical theory, and constructivism. The historical transitions or


id: qualitative-research-20260505-1
file: data/en.wikipedia.org/wiki/Qualitative_research-1.md
category: reference
title: Qualitative research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qualitative_research
date_saved: 2026-05-05T10:02:55.894451+00:00
instance: kb-cron
parent: qualitative-research-20260505-0
summary:
== Data analysis == Qualitative researchers have a number of analytic strategies available to them. === Coding === In general, coding refers to the act of associating meaningful ideas with the data of interest. In the context of qualitative research, interpretative aspects of the coding process are often explicitly recognized and articulated; coding helps to produce specific words or short phrases believed to be useful abstractions from the data. === Pattern thematic analysis === Data may be sorted into patterns for thematic analyses as the primary basis for organizing and reporting the study findings. === Content analysis === According to Krippendorf, "Content analysis is a research technique for making replicable and valid inference from data to their context" (p. 21). It is applied to documents and written and oral communication. Content analysis is an important building block in the conceptual analysis of qualitative data. It is frequently used in sociology. For example, content analysis has been applied to research on such diverse aspects of human life as changes in perceptions of race over time, the lifestyles of contractors, and even reviews of automobiles. == Multi-method qualitative analysis == === Benefits === This is, for example, illustrated by studies on classroom


id: qualitative-research-20260505-2
file: data/en.wikipedia.org/wiki/Qualitative_research-2.md
category: reference
title: Qualitative research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qualitative_research
date_saved: 2026-05-05T10:02:55.894451+00:00
instance: kb-cron
parent: qualitative-research-20260505-0
summary:
=== Limitations of qualitative research === Qualitative research is not without limitations. These limitations include participant reactivity, the potential for a qualitative investigator to over-identify with one or more study participants, "the impracticality of the Glaser-Strauss idea that hypotheses arise from data unsullied by prior expectations," the inadequacy of qualitative research for testing cause-effect hypotheses, and the Baconian character of qualitative research. Participant reactivity refers to the fact that people often behave differently when they know they are being observed. Over-identifying with participants refers to a sympathetic investigator studying a group of people and ascribing, more than is warranted, a virtue or some other characteristic to one or more participants. Compared to qualitative research, experimental research and certain types of nonexperimental research (e.g., prospective studies), although not perfect, are better means for drawing cause-effect conclusions. Glaser and Strauss, influential members of the qualitative research community, pioneered the idea that theoretically important categories and hypotheses can emerge "naturally" from the observations a qualitative researcher collects, provided that the researcher is not guided by preconceptions. The ethologist David Katz wrote "a hungry animal divides the environment into edible and inedible things....Generally speaking, objects change...according to the needs of the animal." Karl Popper


id: qualitative-research-20260505-3
file: data/en.wikipedia.org/wiki/Qualitative_research-3.md
category: reference
title: Qualitative research
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qualitative_research
date_saved: 2026-05-05T10:02:55.894451+00:00
instance: kb-cron
parent: qualitative-research-20260505-0
summary:
== Further reading == Adler, P. A. & Adler, P. (1987). : context and meaning in social inquiry / edited by Richard Jessor, Anne Colby, and Richard A. Shweder OCLC 46597302 Baškarada, S. (2014) "Qualitative Case Study Guidelines", in The Qualitative Report, 19(40): 1-25. Available from [1] Archived 2015-03-26 at the Wayback Machine Boas, Franz (1943). "Recent anthropology". Science. 98 (2546): 311–314, 334–337. Bibcode:1943Sci....98..334B. doi:10.1126/science.98.2546.334. PMID 17794461. Creswell, J. W. (2003). Research design: Qualitative, quantitative, and mixed method approaches. Thousand Oaks, CA: Sage Publications. Denzin, N. K., & Lincoln, Y. S. (2000). Handbook of qualitative research ( 2nd ed.). Thousand Oaks, CA: Sage Publications. Denzin, N. K., & Lincoln, Y. S. (2011). The SAGE Handbook of qualitative research ( 4th ed.). Los Angeles: Sage Publications. DeWalt, K. M. & DeWalt, B. R. (2002). Participant observation. Walnut Creek, CA: AltaMira Press. Fischer, C.T. (Ed.) (2005). Qualitative research methods for psychologists: Introduction through empirical studies. Academic Press. ISBN 0-12-088470-4. Franklin, M. I. (2012), "Understanding Research: Coping with the Quantitative-Qualitative Divide". London/New York. Routledge Giddens, A. (1990). The consequences of modernity. Stanford, CA: Stanford University Press. Gubrium, J. F. and J. A. Holstein. (2000). "The New Language of Qualitative Method." New York: Oxford


id: randomised-non-comparative-trial-20260505-0
file: data/en.wikipedia.org/wiki/Randomised_non-comparative_trial-0.md
category: reference
title: Randomised non-comparative trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomised_non-comparative_trial
date_saved: 2026-05-05T10:02:57.097615+00:00
instance: kb-cron
parent: randomised-non-comparative-trial-20260505-0
summary:
A randomised non-comparative trial, RNCT (or also non-comparative randomised trial), is a type of clinical trial where participants are randomised to different conditions (arms), but where the primary analysis involves comparing each arm separately to a historical control, predefined benchmark or something else, with no formal comparison between the two arms. The study design appears to have arisen in oncology, where single-arm studies are not unusual. It promises reduced sample size requirements. An RNCT acts like multiple single-arm designs run concurrently. A review found RNCTs dating back to 2002, and having been used in high-profile oncology studies and also beyond oncology. The design has been criticised by statisticians. It is unclear what benefit randomisation adds compared to running separate single-arm studies. Pavlos Msaouel described the use of the word "randomisation" as merely being "talismanic" in a 2025 article, it leading readers to think the study has the benefits of a randomised controlled trial (RCT). While the point of an RNCT is not to have a comparison between arms, about half of reported RNCTs still reported some sort of comparison. == References ==


id: randomized-controlled-trial-20260505-0
file: data/en.wikipedia.org/wiki/Randomized_controlled_trial-0.md
category: reference
title: Randomized controlled trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_controlled_trial
date_saved: 2026-05-05T10:02:58.342301+00:00
instance: kb-cron
parent: randomized-controlled-trial-20260505-0
summary:
A randomized controlled trial (RCT) is a type of statistical experiment designed to evaluate the efficacy or safety of an intervention by minimizing bias through the random allocation of participants to one or more comparison groups. In this approach, at least one group receives the intervention or process under study (such as a drug, surgical procedure, medical device or diet), while the other groups receive an alternative treatment, a placebo, or standard care. RCTs are a fundamental methodology in modern clinical trials and have been widely considered one of the highest-quality sources of evidence in evidence-based medicine, due to their ability to reduce selection bias and the influence of confounding factors. However, they have also been criticized for failing to reduce bias in some cases. Participants who enroll in RCTs differ from one another in known and unknown ways that can influence study outcomes, and yet cannot be directly controlled. By randomly allocating participants among compared treatments, an RCT enables statistical control over these influences. Provided it is designed well, conducted properly, and enrolls enough participants, an RCT may achieve sufficient control over these confounding factors to deliver a useful comparison of the treatments studied. == Definition and examples ==


id: randomized-controlled-trial-20260505-1
file: data/en.wikipedia.org/wiki/Randomized_controlled_trial-1.md
category: reference
title: Randomized controlled trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_controlled_trial
date_saved: 2026-05-05T10:02:58.342301+00:00
instance: kb-cron
parent: randomized-controlled-trial-20260505-0
summary:
== Ethics == Although subjects almost always provide informed consent for their participation in an RCT, studies since 1982 have documented that RCT subjects may believe that they are certain to receive treatment that is best for them personally; that is, they do not understand the difference between research and treatment. Determining the amount of information required to ensure informed consent can be difficult, and further research is necessary to determine the prevalence of and ways to address therapeutic misconception. Placebo-controlled trials have been deemed unethical in instances where not receiving treatment may lead to harm for the patient, such as an aggravation of symptoms or risk of death. Crossover trials, active-controlled trials, and other approaches have been used to mitigate this issue, though these options may not always be suitable for study, and have received their own criticism. Active-controlled trials in particular may raise ethical considerations regarding clinical equipoise. Although the principle of equipoise ("genuine uncertainty within the expert medical community... about the preferred treatment") is common to clinical trials and has been applied to RCTs, equipoise may be difficult to ascertain, and the ethics of RCTs have special considerations. It has been argued that equipoise itself is insufficient


id: randomized-controlled-trial-20260505-2
file: data/en.wikipedia.org/wiki/Randomized_controlled_trial-2.md
category: reference
title: Randomized controlled trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_controlled_trial
date_saved: 2026-05-05T10:02:58.342301+00:00
instance: kb-cron
parent: randomized-controlled-trial-20260505-0
summary:
"It eliminates bias in treatment assignment," specifically selection bias and confounding. "It facilitates blinding (masking) of the identity of treatments from investigators, participants, and assessors." "It permits the use of probability theory to express the likelihood that any difference in outcome between treatment groups merely indicates chance." There are two processes involved in randomizing patients to different interventions. First is choosing a randomization procedure to generate an unpredictable sequence of allocations; this may be a simple random assignment of patients to any of the groups at equal probabilities, may be "restricted", or may be "adaptive." A second and more practical issue is allocation concealment, which refers to the stringent precautions taken to ensure that the group assignment of patients are not revealed prior to definitively allocating them to their respective groups. Non-random "systematic" methods of group assignment, such as alternating subjects between one group and the other, can cause "limitless contamination possibilities" and can cause a breach of allocation concealment. However empirical evidence that adequate randomization changes outcomes relative to inadequate randomization has been difficult to detect. === Procedures === The treatment allocation is the desired proportion of patients in each treatment arm. An ideal randomization procedure would achieve the


id: randomized-controlled-trial-20260505-3
file: data/en.wikipedia.org/wiki/Randomized_controlled_trial-3.md
category: reference
title: Randomized controlled trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_controlled_trial
date_saved: 2026-05-05T10:02:58.342301+00:00
instance: kb-cron
parent: randomized-controlled-trial-20260505-0
summary:
"Allocation concealment" (defined as "the procedure for protecting the randomization process so that the treatment to be allocated is not known before the patient is entered into the study") is important in RCTs. In practice, clinical investigators in RCTs often find it difficult to maintain impartiality. Stories abound of investigators holding up sealed envelopes to lights or ransacking offices to determine group assignments in order to dictate the assignment of their next patient. Such practices introduce selection bias and confounders (both of which should be minimized by randomization), possibly distorting the results of the study. Adequate allocation concealment should defeat patients and investigators from discovering treatment allocation once a study is underway and after the study has concluded. Treatment related side-effects or adverse events may be specific enough to reveal allocation to investigators or patients thereby introducing bias or influencing any subjective parameters collected by investigators or requested from subjects. Some standard methods of ensuring allocation concealment include sequentially numbered, opaque, sealed envelopes (SNOSE); sequentially numbered containers; pharmacy controlled randomization; and central randomization. It is recommended that allocation concealment methods be included in an RCT's protocol, and that the allocation concealment methods should be reported in detail in a publication


id: randomized-controlled-trial-20260505-4
file: data/en.wikipedia.org/wiki/Randomized_controlled_trial-4.md
category: reference
title: Randomized controlled trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_controlled_trial
date_saved: 2026-05-05T10:02:58.342301+00:00
instance: kb-cron
parent: randomized-controlled-trial-20260505-0
summary:
=== Relative importance and observational studies === Two studies published in The New England Journal of Medicine in 2000 found that observational studies and RCTs overall produced similar results. The authors of the 2000 findings questioned the belief that "observational studies should not be used for defining evidence-based medical care" and that RCTs' results are "evidence of the highest grade." However, a 2001 study published in Journal of the American Medical Association concluded that "discrepancies beyond chance do occur and differences in estimated magnitude of treatment effect are very common" between observational studies and RCTs. According to a 2014 (updated in 2024) Cochrane review, there is little evidence for significant effect differences between observational studies and randomized controlled trials. To evaluate differences it is necessary to consider things other than design, such as heterogeneity, population, intervention or comparator. Two other lines of reasoning question RCTs' contribution to scientific knowledge beyond other types of studies: If study designs are ranked by their potential for new discoveries, then anecdotal evidence would be at the top of the list, followed by observational studies, followed by RCTs. RCTs may be unnecessary for treatments that have dramatic and rapid effects relative to the expected stable


id: randomized-controlled-trial-20260505-5
file: data/en.wikipedia.org/wiki/Randomized_controlled_trial-5.md
category: reference
title: Randomized controlled trial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_controlled_trial
date_saved: 2026-05-05T10:02:58.342301+00:00
instance: kb-cron
parent: randomized-controlled-trial-20260505-0
summary:
=== Time and costs === RCTs can be expensive; one study found 28 Phase III RCTs funded by the National Institute of Neurological Disorders and Stroke prior to 2000 with a total cost of US$335 million, for a mean cost of US$12 million per RCT. Nevertheless, the return on investment of RCTs may be high, in that the same study projected that the 28 RCTs produced a "net benefit to society at 10-years" of 46 times the cost of the trials program, based on evaluating a quality-adjusted life year as equal to the prevailing mean per capita gross domestic product. The conduct of an RCT takes several years until being published; thus, data is restricted from the medical community for long years and may be of less relevance at time of publication. It is costly to maintain RCTs for the years or decades that would be ideal for evaluating some interventions. Interventions to prevent events that occur only infrequently (e.g., sudden infant death syndrome) and uncommon adverse outcomes (e.g., a rare side effect of a drug) would require RCTs with extremely large sample sizes and may, therefore, best be assessed by observational studies. Due to the costs of running RCTs,


