Convenience Samples for Research

A Brief Overview of the Sampling Technique

College students seated in a lecture hall represent a commonly used type of research convenience sample.
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A convenience sample is a non-probability sample in which the researcher uses the subjects that are nearest and available to participate in the research study. This technique is also referred to as "accidental sampling," and is commonly used in pilot studies prior to launching a larger research project.

Key Takeaways: Convenience Samples

  • A convenience sample consists of research subjects who were chosen for a study because they could be recruited easily.
  • One disadvantage of convenience sampling is that subjects in a convenience sample may not be representative of the population the researcher is interested in studying.
  • One advantage of convenience sampling is that data can be collected quickly and for a low cost.
  • Convenience samples are often used in pilot studies, through which researchers can refine a research study before testing a larger and more representative sample.

Overview

When a researcher is eager to begin conducting research with people as subjects, but may not have a large budget or the time and resources that would allow for the creation of a large, randomized sample, she may choose to use the technique of convenience sampling. This could mean stopping people as they walk along a sidewalk, or surveying passersby in a mall, for example. It could also mean surveying friends, students, or colleagues to which the researcher has regular access.​

Given that social science researchers are also often college or university professors, it is quite common for them to begin research projects by inviting their students to be participants. For example, let’s say that a researcher is interested in studying drinking behaviors among college students. The professor teaches an introduction to sociology class and decides to use her class as the study sample, so she passes out surveys during class for the students to complete and hand in.

This would be an example of a convenience sample because the researcher is using subjects that are convenient and readily available. In just a few minutes, the researcher is able to conduct a study with possibly a large research sample, given that introductory courses at universities can have as many as 500-700 students enrolled in a term. However, as we’ll see below, there are both pros and cons of using convenience samples such as this one.

Disadvantages of Convenience Samples

One disadvantage highlighted by the above example is that a convenience sample is not representative of all college students, and therefore the researcher would not be able to generalize her findings to the entire population of college students. The students enrolled in the introductory sociology class, for example, might be mostly first-year students. The sample may be unrepresentative in other ways, such as by religiosity, race, class, and geographical region, depending on the population of students enrolled at the school.

Moreover, the students in the introductory sociology class may not be representative of students at all universities—they may differ from students at other universities on some of these dimensions as well. For example, researchers Joe Henrich, Steven Heine, and Ara Norenzayan found that psychology research studies often involve American college students, who tend to be unrepresentative of the global population as a whole. Consequently, Henrich and his colleagues suggest, study results could look different if researchers studied non-students or individuals from non-Western cultures.

In other words, with a convenience sample, the researcher is unable to control the representativeness of the sample. This lack of control may cause a biased sample and research results, and thus limits the wider applicability of the study.

Advantages of Convenience Samples

While the results of studies using convenience samples may not necessarily be applicable to the larger population, the results could still be useful. For example, the researcher could consider the research a pilot study and use the results to refine certain questions on the survey or to come up with more questions to include in a later survey. Convenience samples are often used for this purpose: to test certain questions and see what kind of responses arise, and use those results as a springboard to create a more thorough and useful questionnaire.

A convenience sample also has the benefit of allowing for a low- to no-cost research study to be conducted, because it uses the population that is already available. It is also time-efficient because it allows the research to be conducted in the course of the researcher's everyday life. As such, a convenience sample is often chosen when other randomized sampling techniques are simply not possible to achieve.