Empirical studies of Crew Resource Management (CRM) training effectiveness were subjected to meta-analysis. Sixteen CRM evaluation studies were found to fulfill the a priori criteria for inclusion in the meta-analysis. The metrics of CRM training effectiveness analyzed were: reactions, attitudes, knowledge, and behaviors. CRM trained participants responded positively to CRM (a mean of four on a five point Likert scale) and the training had large effects on the participants' attitudes and behaviors, and a medium effect on their knowledge. The findings from the meta-analysis are encouraging for the effectiveness of CRM training. However, there is a need for researchers, and reviewers, to be more rigorous about the data included in papers reporting CRM evaluation to allow effect sizes to be calculated.2