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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Field experiment | 2/2 | https://en.wikipedia.org/wiki/Field_experiment | reference | science, encyclopedia | 2026-05-05T09:50:14.421917+00:00 | kb-cron |
== Limitations == There are limitations of and arguments against using field experiments in place of other research designs (e.g. lab experiments, survey experiments, observational studies, etc.). Given that field experiments necessarily take place in a specific geographic and political setting, there is a concern about extrapolating outcomes to formulate a general theory regarding the population of interest. However, researchers have begun to find strategies to effectively generalize causal effects outside of the sample by comparing the environments of the treated population and external population, accessing information from larger sample size, and accounting and modeling for treatment effects heterogeneity within the sample. Others have used covariate blocking techniques to generalize from field experiment populations to external populations. Noncompliance issues affecting field experiments (both one-sided and two-sided noncompliance) can occur when subjects who are assigned to a certain group never receive their assigned intervention. Other problems to data collection include attrition (where subjects who are treated do not provide outcome data) which, under certain conditions, will bias the collected data. These problems can lead to imprecise data analysis; however, researchers who use field experiments can use statistical methods in calculating useful information even when these difficulties occur. Using field experiments can also lead to concerns over interference between subjects. When a treated subject or group affects the outcomes of the nontreated group (through conditions like displacement, communication, contagion etc.), nontreated groups might not have an outcome that is the true untreated outcome. A subset of interference is the spillover effect, which occurs when the treatment of treated groups has an effect on neighboring untreated groups. Field experiments can be expensive, time-consuming to conduct, difficult to replicate, and plagued with ethical pitfalls. Subjects or populations might undermine the implementation process if there is a perception of unfairness in treatment selection (e.g. in 'negative income tax' experiments communities may lobby for their community to get a cash transfer so the assignment is not purely random). There are limitations to collecting consent forms from all subjects. Comrades administering interventions or collecting data could contaminate the randomization scheme. The resulting data, therefore, could be more varied: larger standard deviation, less precision and accuracy, etc. This leads to the use of larger sample sizes for field testing. However, others argue that, even though replicability is difficult, if the results of the experiment are important then there a larger chance that the experiment will get replicated. As well, field experiments can adopt a "stepped-wedge" design that will eventually give the entire sample access to the intervention on different timing schedules. Researchers can also design a blinded field experiment to remove possibilities of manipulation.
== Examples == The history of experiments in the lab and the field has left longstanding impacts in the physical, natural, and life sciences. Modern use field experiments has roots in the 1700s, when James Lind utilized a controlled field experiment to identify a treatment for scurvy. Other categorical examples of sciences that use field experiments include:
Economists have used field experiments to analyze discrimination (e.g., in the labor market, in housing, in the sharing economy, in the credit market, or in integration), health care programs, charitable fundraising, education, information aggregation in markets, and microfinance programs. Engineers often conduct field tests of prototype products to validate earlier laboratory tests and to obtain broader feedback. Researchers in social psychology often use field experiments, such as Stanley Milgram's Stanford Prison Experiment and Robert Cialdini's door-in-the-face study. Agricultural science researcher R.A. Fisher analyzed randomized actual "field" experimental data for crops. Political Science researcher Harold Gosnell conducted an early field experiment on voter participation in 1924 and 1925. Ecology Joseph H. Connell’s field experiment.
== See also == Field research
== References ==