The Campbell Collaboration's systematic review of school-based anti-bullying interventions does not meet mandatory methodological standards.

Systematic reviews are expected to use transparent methods and follow relevant methodological standards. Readers should be concerned when these expectations are not met, because transparency and rigor enhance the trustworthiness of results and conclusions. In the tradition of Donald T. Campbell, there is need for more public debate about the methods and conclusions of systematic reviews, and greater clarity regarding applications of (and adherence to) published standards for systematic reviews.