Quality Assurance: Qualitative Data (Bouzar and Laurent [40])
1. Epistemological position. Did the authors provide philosophical grounding for what has been done and why? e.g., post positivist; realist; interpretative; and constructivist.	Implicitly, through the insistence of a multidisciplinary approach, which inherently involved different epistemologies, i.e., social, psychological, psychoanalytical, geopolitical and religious.
2. Was bias addressed, if so, how?	Implicitly, through the need to have social, psychological, psychoanalytical, geopolitical and religious analyses (i.e., a multidisciplinary analysis) to understand the radicalisation stages that lead to a commitment to extremist violence.
3. Was it ensured that “valid” and “credible” accounts were given that reflect an accurate portrayal of the social reality? How?	Yes, with quotes from the semi-structured interviews.
4. Was there a quality assurance checklist?	Not stated.
5. Was there ongoing quality assurance, e.g., fieldnotes and field diaries.	Not stated.
6. Reflexivity of researcher’s position: was there transparency in the decisions made and the assumptions held?	Implied through the multidisciplinarity but not stated.
7. Comprehensiveness of approach: was the study systematically designed, conducted and analysed?	NA—retrospective case study.