n-Sizes, Attributes, and A Priori Sampling: A Qualitative Sampling Model for Large, Heterogeneous Populations

Qualitative sampling in the age of Big Data requires tactful negotiation. Although qualitative research aims to explore the depth as opposed to breadth of experiences, opinions, or beliefs of individuals regarding a unique phenomenon, stakeholders or sponsors might not always be convinced that small sample sizes can yield big results. Intimate population awareness, identification of attributes of importance, selection of a purposeful numbers game, and strategic use of instruments can aid in appropriate sampling approaches for large, heterogeneous populations. This paper reviews the principles of nonprobability sampling, summarizes key qualitative sampling characteristics to consider, and provides a set of examples for negotiating sample sizes in the era of Big Data.