Table 1.

Final definition for qualitative sampling, including methodological tradition-specific variations

Term	Definition and tradition-specific variations
Sampling	The selection of specific data sources from which data are collected in order to address the research objectives
In grounded theory	What is selected (i.e., the sampling unit) in theoretical sampling is unclear or inconsistent between authors (i.e., it may not simply be data sources)
In phenomenology	What is selected is restricted to people only (i.e., a single type of data source)
In case study	What is selected includes cases (i.e., in addition to data sources)

Developed after numerous iterations in the methods overview on sampling [18]