How to better communicate the likely effectiveness of proposed training: Interpreting meta-analytic results for (and with) an applied audience

Whether to develop and/or conduct training can represent a significant decision for organizations due to associated financial, personnel, and time demands. Various stakeholders in that decision will want to know what to expect from such training, including its likely effectiveness. Informing such stakeholders of the magnitude of relevant previous results - from a single study or, better, from studies aggregated via a meta-analysis - can help their decisions to be as informed as possible. But explanations of the size of training effects as found in the literature are not always phrased in a way easy for an applied audience to understand. This brief article clarifies the 'percent improvement due to training' interpretation of d, and extends it to differing rates of pre-training success. This in turn suggests that customer involvement in estimating appropriate base-line success rates could make interpretations of the degree of training effectiveness more organizationally specific and hence more useful.