Purposeful sampling is widely used in qualitative research for the identification and selection of information-rich cases related to the phenomenon of interest. Although there are several different purposeful sampling strategies, criterion sampling appears to be used most commonly in implementation research.

What is criterion purposive sampling?

Criterion sampling involves the selection of sample based on some pre-established criteria. This criteria is of importance to the research in most significant way. This kind of sampling helps researcher study a very specific or narrow criteria and understand the implications of it.

What is a criterion sample?

Criterion sampling involves the identification of particular criterion of importance, articulation of these criterion, and systematic review and study of cases that meet the criterion. The reason for undertaking criterion sampling is to identify major system weaknesses for improvement.