Purpose of Review

This review discusses design and methodological challenges specific to measuring bystander actions in the evaluation of bystander-based violence prevention programming. “Bystanders” are defined as people who are present immediately before, during and/or after a violent event, but are not a perpetrator nor the intended victim. Bystander-based violence prevention programs seek to prevent or mitigate violent events by empowering bystanders to intervene on acts of violence and social norms that promulgate violence.

Recent Findings

Effective bystander-based violence prevention programs demonstrate increased bystander intentions, actions, and attitudes [Bringing in the Bystander: Banyard et al. J Community Psychol. 2007;35:463-481; iSCREAM: McMahon et al. Health Education Research. 2015;30(4):554-568; The Men's Project: Gidycz et al. Violence Against Women. 2011;7(6):720-742; and Green Dot: Coker et al. Violence Against Women 2011;17:777-796] lowered violence acceptance scores (Coker et al. Violence Against Women 2011;17:777-796; Banyard et al. J Coll Stud Dev 2009;50(4)446-457; Cares et al. Violence Against Women. 2015;21:65-87; McMahon et al. Health Education Research. 2015;30(4):554-568; Moynihan et al. J Interper Viol. 2015;30:110-132) and reduce sexual violence perpetration and victimization (Coker et al. Am J Prev Med. 2017;52(5):566-578; Millet et al. Am J Prev Med 2013;45(1):108-112; Gidcyz et al. Violence Against Women. 2011;7(6):720-742). However, bystander-based violence prevention programs are methodologically challenging to evaluate, due to the wide diversity of programs being implemented and the multifactorial and contextual nature of acts of violence.

Summary

Measures of bystander actions temporally-connected to specific, high-risk opportunities are recommended approaches to capture bystander experiences and address the methodological challenges in measuring bystander actions and evaluating violence prevention programming.