A pilot experiment, also called a pilot study, is a small scale preliminary study conducted in order to evaluate feasibility, time, cost, adverse events, and effect size (statistical variability) in an attempt to predict an appropriate sample size and improve upon the study design prior to performance of a full-scale research project.[1] Pilot studies, therefore, may not be appropriate for case studies. They are frequently carried out before large-scale quantitative research, in an attempt to avoid time and money being wasted on an inadequately designed project. A pilot study is usually carried out on members of the relevant population, but not on those who will form part of the final sample. This is because it may influence the later behavior of research subjects if they have already been involved in the research.[2]
A pilot experiment is often used to test the design of the full-scale experiment which then can be adjusted. It is a potentially valuable insight and should anything be missing in the pilot study it can be added to the full-scale (and more expensive) experiment to improve the chances of a clear outcome.
Often in engineering applications, pilot experiments are used to sell a product and provide quantitative proof that the system has potential to succeed on a full scale basis. Pilot experiments are also used to reduce cost, as they are less expensive than full experiments. If there is not enough reason to provide full scale applications, pilots can generally provide this proof.
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 in public action, their usefulness as a strategy for change has been questioned, at least in the domain of environmental management.[3] It is argued that extrapolation from a pilot study to large scale environmental strategy cannot be assumed to be possible, partly due to the exceptional resources and favourable conditions that often accompanies a pilot study.