Table 1.

Process to determine sufficient sample size

Process	Decision-making considerations	Determination
Study aim	Narrow or broad	Narrow: focus is specifically on the development of collective identity
Sample specificity	Dense or sparse	Dense: participants would have a spectrum of experiences given the group was more than a year old Participants joined the group at various points during the group life cycle Participants different levels of participation in the group to get a broad range of experiences Focus on quality of interactions as the key factor
Established theory	Applied or not	Applied: Social identity approach
Quality of dialogue	Strong or weak	Strong: Length of interviews averaged 55 min Conversational structure using interview guide where required Reflective notes following interviews identified key areas covered and areas that could require more information
Analysis strategy	Case or cross case	Cross case: Use of inductive and deductive reflexive thematic analysis across entire dataset Reflective notes assessed information gathered to see if adding something new or repetition