Meta-analysis: In Practice

The practice of meta-analysis is concerned with the details of implementation of a research synthesis that ensure the validity and robustness of the results from that synthesis. In this article, selected topics are discussed that represent current intellectual themes in the practice of meta-analysis, such as, (i) the role of decisions and judgments, particularly judgments about similarity of studies; (ii) the importance of sensitivity analysis to investigate the robustness of those decisions; and (iii) the role research synthesis plays in the process of scientific discovery. Brief illustrations of the role meta-analysis plays in explanation, program evaluation, and in informing policy decisions are presented.