Purposive Selection

Because the goal of qualitative research is enriching the understanding of an experience, it needs to select fertile exemplars of the experience for study. Such selections are purposeful and sought out; the selection should not be random or left to chance. The concern is not how much data were gathered or from how many sources but whether the data that were collected are sufficiently rich to bring refinement and clarity to understanding an experience.

The purposive selection of data sources involves choosing people or documents from which the researcher can substantially learn about the experience. Patton has said that it is important to select “information- rich cases for study in depth. Information-rich cases are those from which one can learn a great deal about issues of central importance to the purpose of the research, thus the term purposive sampling. Merriam gives the following advice to qualitative researchers:

To begin with, since you are not interested in ‘how much’ or ‘how often,’ random sampling makes little sense. Instead, since qualitative inquiry seeks to understand the meaning of a phenomenon from the perspectives of the participants, it is important to select a sample from which most can be learned. This is called a purposive or purposeful sample. Individuals who can provide relevant descriptions of an experience are primarily those who have had or are having the experience.