Convenience sampling

Convenience sampling (also known as grab sampling, accidental sampling, or opportunity sampling) is a type of non-probability sampling that involves the sample being drawn from that part of the population that is close to hand. That is, a sample population selected because it is readily available and convenient, as researchers are drawing on relationships or networks to which they have easy access. The researcher using such a sample cannot scientifically make generalizations about the total population from this sample because it would not be representative enough. For example, if the interviewer was to conduct such a survey at a shopping center early in the morning on a given day, the people that he/she could interview would be limited to those given there at that given time, which would not represent the views of other members of society in such an area, if the survey was to be conducted at different times of day and several times per week. Another common example occurs with paid focus groups designed to study consumer responses to new or changed products. Only those people with the free time and inclination to participate are studied. In addition, these groups may also exhibit constrained financial circumstances that see them value participating in these studies as a worthwhile use of their time. These groups may not be representative of the target market of consumers for the product. An example might be a paid focus group surveying consumer sentiments towards an expensive watch. Those who elect to participate in the study may be of a demographic highly unlikely to ever buy an expensive watch. While it is convenient to use this paid focus group to study the sentiment towards the expensive watch, the results are unlikely to be representative of potential customers for the watch itself. This type of sampling is most useful for pilot testing. Credibility of a researcher's results by convenience sampling will depend on convincing the reader that the sample chosen equates to a large degree of the population from which they are drawn.

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