Sampling is the process of selecting participants for your study or evaluation. In cases where the entire group of people that you are studying is small, it is desirable to sample all of them. This would be the case, for example, with a group of 10 artists who are core to the arts project, or 20 community organizers who are linking arts-based efforts to activism efforts. When the population is so large that you cannot include all participants in your study, for example a whole city’s population, or all residents of a neighborhood, the commonly accepted practice is to select a sample based on agreed-upon criteria.
In general, when the population is large, the best and most commonly accepted practice is to randomly select respondents. Random sampling helps to ensure that the findings from your sample are likely to reflect the characteristics of the entire population that you are studying. In instances where participants hesitate to be interviewed, offering incentives (such as cash, free tickets or other items) may help.
However, just as important (depending on the type of research being conducted), is purposeful sampling, in which people are intentionally selected because they have a distinct set of characteristics that are of interest to the researcher. Examples of purposeful samples might be audience members who attend a series of public dialogues that integrate performance prompts, people self-described as opposed to an issue, students who volunteer in a community revitalization project, or artists who participate in civic engagement skill-building workshops. Often helpful in small studies, the reasons why a purposeful sample would be used are:
- To get adequate representation, where random sampling would be impossible, such as to evaluate an arts program that serves homeless people in a particular jurisdiction.
- To deliberately select typical cases, such as artists in a particular jurisdiction who volunteered in the presidential election.
- To examine critical cases, such as a teenage mothers who had found ways to complete long-term programs that an organization had hosted.
- To compare differences between cases, such as the differences between artists who work in partnership with community arts organizers versus those who conduct similar work on their own.