DETECTING MODERATORS WITH META‐ANALYSIS: AN EVALUATION AND COMPARISON OF TECHNIQUES

The present study evaluated accuracy levels of seven techniques for ascertaining, after a meta‐analysis, whether moderators are present or not: (a) SH‐75% rule for uncorrected r, (b) SH‐75% rule for corrected r, (c) SH‐95% rule for uncorrected r, (d) SH‐95% rule for corrected r, (e) the Q statistic; (f) inclusion of 0 in the credibility interval around the corrected r, and (g) the size of the interval. Using Monte Carlo data which were defined by various parameters including sample based artifacts, comparisons of Type I and power determinations were generated. Findings showed that when differences between population correlations were small, power levels for all techniques were relatively low. Overall, SH rules and the Q statistic had greater power but higher Type I error rate than credibility intervals. Because of the high Type I error rate associated with both of the SH‐95% techniques and the low power found with the credibility intervals, the SH‐75% rules and Q statistic are recommended. Limitations and some practical implications for the findings are discussed.