The Meta-Plot: A Graphical Tool for Interpreting the Results of a Meta-Analysis

Abstract

The meta-plot is a descriptive visual tool for meta-analysis that provides information on the primary studies in the meta-analysis and the results of the meta-analysis. More precisely, the meta-plot portrays (1) the precision and statistical power of the primary studies in themetaanalysis, (2) the estimate and confidence interval of a random-effects meta-analysis, (3) the results of a cumulative random-effects metaanalysis yielding a robustness check of the meta-analytic effect size with respect to primary studies' precision, and (4) evidence of publication bias. After explaining the underlying logic and theory, the meta-plot is applied to two cherry-picked meta-analyses that appear to be biased and to 10 randomly selected meta-analyses from the psychological literature. We recommend accompanying any meta-analysis of common effect size measures with the meta-plot.