Convenience Sample

A convenience sample can be defined as a sample in which research participants are selected based on their ease of availability. Essentially, individuals who are the most ready, willing, and able to participate in the study are the ones who are selected to participate. In qualitative research, it may be helpful to use a convenience sample to test the appropriateness of interview questions in an inexpensive and quick way by approaching an interested group of people first before embarking on a larger, longer, and more expensive study.

One common example of convenience sampling is found in psychology, where introductory psychology students are frequently recruited to answer psychologically oriented research questions, such as their motivation to exercise, as part of their introductory coursework in psychological research. In essence, these students have been asked to answer questions about their motivation to exercise because they are readily accessible. That is, the researcher could recruit them directly from introductory psychology classes and did not need to venture into the wider community to conduct the research.

Although this type of sampling technique can most assuredly save the researcher time and money at the recruitment stage, it is not without its drawbacks. If the researcher recruits students from a psychology class at a particular academic institution, for example, it is difficult to know whether or not the students' motivation to exercise is reflective of motivation to exercise in other contexts. Similarly, it may be that students are perhaps less motivated to exercise than members of the larger society because they are too busy with their coursework. Hence, it is difficult to assess whether or not the study's findings regarding motivation to exercise can apply to students and the population at large. For this reason, convenience samples can lack transferability (or external validity) in qualitative research. In quantitative projects, it can be difficult to generalize the results beyond the original sample from which the data were collected. However, because qualitative researchers are typically interested in studying specific groups of people rather than generalizing to larger populations, it may be tempting for researchers to view this issue as a less significant problem than it is for quantitative researchers. However, it is still important to be aware that the participants recruited are not necessarily reflective of the population being studied. For example, when recruiting for a study about the views of breast-feeding mothers, it is possible that those who answer the advertisement and come to talk to the researchers are the ones with the strongest opinions. They may be individuals who have the most vested interest in sharing their stories because they want to effect change in society's attitudes toward breast-feeding. With this in mind, qualitative researchers should be aware that the people who are recruited most readily are not necessarily reflective of all viewpoints.

In sum, a convenience sample can be described as a group of participants who have been recruited for a given study because they were readily accessible. Using a convenience sample can be both time- and [Page 125]cost-effective, but caution about the nature of the results should be considered in their interpretation.

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