Meta-analysis multiplicity, the concept of conducting multiple tests of statistical significance within one study, is an underdeveloped literature (Tendal, Nüesch, Higgins, Jüni, & Gøtzsche, 2011). We address this issue by considering how Type I errors can impact meta-analytic results, suggest how statistical power may be affected through the use of multiplicity corrections, and propose how meta-analysts should analyze multiple tests of statistical significance. The context for this study is a meta-review of meta-analyses published in two leading review journals in education and psychology. Our review of 130 meta-analyses revealed a strong reliance on statistical significance testing without considering of Type I errors or the use of multiplicity corrections. In order to provide valid conclusions, meta-analysts must consider these issues prior to conducting the study
