Theoretical Sampling

Identifying Appropriate Data Sources

Theoretical sampling is an efficient means of sourcing data, particularly in qualitative research. Qualitative studies generally produce voluminous quantities of textual data. Theoretical sampling assists the researcher to maintain focus by directing the generation or collection of data that has specific value to the study. Theoretical sampling may dictate the type and source of data required as well as most appropriate method by which it can be obtained. For example, a researcher might identify through theoretical sampling that a particular type of data could best be gathered via focus group rather than individual interview or via observation rather than a survey.

Achieving Saturation

Most forms of qualitative research rely on data saturation to determine whether sufficient data have been generated or collected and whether the analysis is complete. Theoretical sampling enables the researcher to secure data that directly relate to the developing themes, codes, or categories that comprise their analysis, without having to wade through large quantities of repetitious data that have little value for the analysis. This concept is particularly important in grounded theory, where the researcher is specifically aiming to identify a core category and process to anchor the analysis.

Building Theory

A theory is a framework that explains abstract concepts. When undertaking research where the aim is to build theory, maintaining connection between the categories as they are developed is critical. Theoretical sampling facilitates this process, as it enables the researcher to describe the properties and dimensions of concepts and the nature of relationships between them. In methodologies such as grounded theory, the ability to explicate key components of a developing theory and explain the process that connects them is critical in ensuring that the resultant product is grounded in the data.

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