A pilot study, pilot project, pilot test, or pilot experiment is a small-scale preliminary study conducted to evaluate feasibility, duration, cost, adverse events, and improve upon the study design prior to performance of a full-scale research project.
Pilot experiments are frequently carried out before large-scale quantitative research, in an attempt to avoid time and money being used on an inadequately designed project. A pilot study is usually carried out on members of the relevant population. A pilot study is used to formulate the design of the full-scale experiment which then can be adjusted. The pilot study is potentially a critical insight to clinical trial design, recruitment and sample size of participants, treatment testing, and statistical analysis to improve the power of testing the hypothesis of the study. Analysis from the pilot experiment can be added to the full-scale (and more expensive) experiment to improve the chances of a clear outcome.
In sociology, pilot studies can be referred to as small-scale studies that will help identify design issues before the main research is done. Although pilot experiments have a well-established tradition, their usefulness as a strategy for change has been questioned, at least in the domain of environmental management. Extrapolation from a pilot study to large scale strategy may not be assumed as possible, partly due to the exceptional resources and favorable conditions that accompany a pilot study.
In clinical research, studies conducted in preparation for a future randomized controlled trial are known as "pilot" and "feasibility" studies, where pilot studies are a subset of feasibility studies. A feasibility study asks whether the study should proceed, and if so, how. A pilot study asks the same questions, but also has a specific design feature: in a pilot study, a future study is conducted on a smaller scale, which, if having produced positive results, may lead to a Phase I clinical trial. The use of pilot and feasibility studies to estimate treatment effect is controversial, with ongoing methodologic discussion about appropriateness.
A checklist was published in 2016 to provide guidance on how to report pilot trials.
- Thabane L, Ma J, Chu R, Cheng J, Ismaila A, Rios LP, et al. (January 2010). "A tutorial on pilot studies: the what, why and how". BMC Medical Research Methodology. 10 (1): 1. doi:10.1186/1471-2288-10-1. PMC 2824145. PMID 20053272.
- Lewis M, Bromley K, Sutton CJ, McCray G, Myers HL, Lancaster GA (February 2021). "Determining sample size for progression criteria for pragmatic pilot RCTs: the hypothesis test strikes back!". Pilot and Feasibility Studies. 7 (1): 40. doi:10.1186/s40814-021-00770-x. PMC 7856754. PMID 33536076.
- Billé R, Duchemin B (February 2010). "Action without change? On the use and usefulness of pilot experiments in environmental management". SAPIEN. Surveys and Perspectives Integrating Environment and Society. 4 (1).
- Leon AC, Davis LL, Kraemer HC (May 2011). "The role and interpretation of pilot studies in clinical research". Journal of Psychiatric Research. 45 (5): 626–629. doi:10.1016/j.jpsychires.2010.10.008. PMC 3081994. PMID 21035130.
- Eldridge SM, Lancaster GA, Campbell MJ, Thabane L, Hopewell S, Coleman CL, Bond CM (2016). "Defining Feasibility and Pilot Studies in Preparation for Randomised Controlled Trials: Development of a Conceptual Framework". PLOS ONE. 11 (3): e0150205. Bibcode:2016PLoSO..1150205E. doi:10.1371/journal.pone.0150205. PMC 4792418. PMID 26978655.
- "The drug development process: Step 3: Clinical research". US Food and Drug Administration. 4 January 2018. Retrieved 29 March 2021.
- Sim J (December 2019). "Should treatment effects be estimated in pilot and feasibility studies?". Pilot and Feasibility Studies. 5 (1): 107. doi:10.1186/s40814-019-0493-7. PMC 6712606. PMID 31485336.
- Eldridge SM, Chan CL, Campbell MJ, Bond CM, Hopewell S, Thabane L, Lancaster GA, et al. (PAFS Consensus Group) (October 2016). "CONSORT 2010 statement: extension to randomised pilot and feasibility trials". BMJ. 355: i5239. doi:10.1136/bmj.i5239. PMC 5076380. PMID 27777223.