Commentary on Valentine, Jeffrey, et al. Replication in Prevention Science

Excerpt

The Valentine et al. paper provides a first-step analysis of some key issues in replication. The paper acknowledges the question of what is to be considered a replication and introduces the importance of understanding the purpose of a replication study. Importantly, the paper recognizes the current development of the field of prevention science in which we are faced with few replications to consider, with sometimes a maximum of two studies. To illustrate, the Blueprints for Violence Prevention project at the University of Colorado has reviewed evaluations of 895 prevention programs. Of these, less than 13% have been subjected to a second study, only some of which would likely have been considered true replications. The Valentine et al. paper focuses primarily on how information should be summarized across multiple studies, where inclusion as replication is not uncertain, and where the needed information to judge replication by the particular standard of interest is accessible. We agree with the paper’s conclusions about how evidence from multiple studies that meet these criteria should be summarized to answer the question, “What does the available evidence say about the size of the effect attributable to Intervention A?” …