This chapter provides a general introduction to meta-analysis, and presents the steps involved in synthesizing research. It considers some options that reviewers should consider as they proceed through these steps. The chapter discusses standards for conducting and evaluating quantitative reviews. It evaluates meta-analysis relative to primary research and other methods of testing hypotheses. The chapter uses the term "meta-analysis" to refer broadly to the entirety of the process, including both quantitative and qualitative aspects. It considers two-variable effect size indexes, otherwise known as indexes of association, and addresses arithmetic means. To determine the relation between study characteristics and the magnitude of the effect sizes, analysts fit models using a form of weighted ordinary least squares regressions. The growing numbers of studies on personality and social psychology's central phenomena dictate that, in the future, greater importance will be accorded to high-quality meta-analyses of these knowledge bases.