Illustration of a multilevel model for meta-analysis

Clustering effect and non-zero intraclass correlation produce the variability that can be observed in meta-analytic data. Statistical modeling is shown to provide a flexible approach to capturing and describing this empirical variability. The most common multilevel approach to analyzing data from meta-analysis is illustrated in this article with a set of 177 studies of behavioral therapies. © 2007 American Counseling Association. All rights reserved.Link_to_subscribed_fulltex