This article evaluates how scientific methods are used and how complainants are questioned about child sexual abuse, based on 17 studies commissioned by the Royal Commission into Institutional Responses to Child Sexual Abuse. Qualitative and quantitative methods were used to assess the practices and processes used to manage witnesses’ vulnerability and psychological distress to draw out more credible and reliable evidence. The evaluation found a range of practices based on unsupported assumptions about victim behaviour and memory, judicial instructions and interventions, cross-examination strategies and quality issues with recordings of pre-interview and CCTV cross-examination by police.