Abstract
Meta-analysis consists of a set of statistical techniques that aims to combine the results of two or more primary studies. It enables the calculation of point and interval estimates of some population parameter, usually a measure of effect size. The aim of this article is to introduce fundamental concepts of meta-analysis and its applications for psychologists and psychology students. The article: (1) introduces the logic of meta-analysis, its uses and common criticisms levied against it; (2) presents two computational models of meta-analysis commonly used by researchers; and (3) addresses two issues associated with the correct interpretation of results from meta-analyses: heterogeneity and subgroup analysis. A worked example illustrates the concepts throughout the article. The Supplementary Materials contain a worked example of the models presented in the text, a script in R language that allows the reader to reproduce the results, and a commented list of additional sources.
Keywords:
meta-analysis; systematic review; literature review; effect size; forest plot