This post is an introduction to a series of posts about meta-analysis. We think that many, perhaps most, meta-analyses in the behavioral sciences are invalid. In this introductory post, we make that case with arguments. In subsequent posts, we will make that case by presenting examples taken from published meta-analyses.

We have recently written a short article for Nature Reviews Psychology in which we briefly described some fundamental problems with meta-analysis, and proposed an alternative way to generate more productive and less misleading literature reviews (.htm). Because of space constraints, in that article we couldn’t fully articulate our concerns with meta-analysis, and we were unable to include many examples. But we can do that here, over the course of a few posts.