Systematic Review of Conceptual Approaches and Operationalizations of Radicalization Facets

This protocol outlines the process for a systematic review with: a) identifying definitions and conceptualizations of radicalization and its determinants paired with b) investigating respectively, valid measures, quantitative empirical research has brought up to capture the phenomenon in question. Determinants of radicalization (comprising psychological, social-psychological or environmental dimensions), as well as outcomes, along the axis of violent, non-violent radicalization, besides non-radicalization are considered eligible. Furthermore, this review attempts to c) characterize how well the identified instruments capture radicalization and d) discern future avenues via an evidence gap map. In addition, as an exploratory part, a co-citation network, investigating the stability and size of schools of thought in the light of radicalization concepts will be conducted. Empirical articles will be screened (first based on title and abstract and then full-text screening) according to inclusion and exclusion criteria relating to the relevance, population, setting and availability of research. Instruments identified will be appraised to establish their reliability and validity. Thereby, extracted data of concepts and operationalizations will inform an evidence structure regarding self-reported, experimental and unobtrusive trace data and reveal gaps in evidence.