Appendix 3 – Basic Methods of Sample Selection for Purposeful Sampling

There are many different ways to select a sample for purposeful sampling. This appendix provides examples of basic methods in each of four main categories:

• single significant case
• comparison-focused sampling
• group characteristics sampling
• mixed, stratified, and nested sampling methods

It also includes two illustrative case studies in which the context of a real audit report is used as a basis from which to consider how an additional sample method might have been selected and applied.

This material is largely based on Patton (2015). The U.S. Government Accountability Office (2017) also provides a useful document that includes information on many of these sampling techniques, as well as examples.

• PreviousAppendix 2 – Unbiased Methods of Selection for Generalizable Sampling
• NextSingle Significant Case