The Synthesis of Partial Effect Sizes

In this article we focus on three partial effect sizes for the correlation (r) family of effects: the standardized slope (b), the partial correlation (rp), and the semi-partial correlation (rsp). These partial effect sizes are useful for meta-analyses in two common situations: when primary studies reporting regression models do not report bivariate correlations, and when it is of specific interest to partial out the effects of other variables. We clarify the use of these three indices in the context of meta-analysis and describe how the indices can be estimated and analyzed. We provide examples of syntheses of these partial effect sizes using a published social work meta-analysis. Finally, we share practical recommendations for meta-analysts wanting to use such indices.