Theoretical sampling

Theoretical sampling refers to the process of choosing new research sites or cases to compare with ones that have already been studied. It is one of the tools of qualitative research. The term was coined by Barney Glaser and Anselm Strauss in 1967.

The goal of theoretical sampling is not the same as with the probabilistic sampling; the researcher's goal is not the representative capture of all possible variations, but to gain a deeper understanding of analysed cases and facilitate the development of analytic frame and concepts used in their research. In doing so, the researcher can ask himself "What is actually happening here?", "Under what conditions does this happen?", "What is the data a study of?" or "What categories does this incident indicate". Maybe it will become apparent that more information is needed to saturate categories under development.

Theoretical sampling can be viewed as a technique of data triangulation: using independent pieces of information to get a better fix on something that is only partially known or understood.

See also

• Grounded theory
• Sampling (statistics)
• Sampling (case studies)

References

• Charles C. Ragin, 'Constructing Social Research: The Unity and Diversity of Method', Pine Forge Press, 1994, ISBN 0-8039-9021-9
• Barney G. Glaser & Anselm L. Strauss, 'The Discovery of Grounded Theory: Strategies for Qualitative Research', Chicago, Aldine Publishing Company, 1967, ISBN 0-202-30260-1