A NOTE ON THE SAMPLING VARIANCE OF THE MEAN UNCORRECTED CORRELATION IN METAANALYSIS AND VALIDITY GENERALIZATION

This article compares the accuracy of several formulas for the standard error of the mean uncorrected correlation in meta-analytic and validity generalization studies. The effect of computing the mean correlation by weighting the correlation in each study by its sample size is also studied. On the basis of formal analysis and simulation studies, it is concluded that the common formula for the sampling variance of the mean correlation, V(t) = V(r)/K where K is the number of studies in the meta-analysis, gives reasonably accurate results. This formula gives accurate results even when sample sizes and rho-s are unequal and regardless of whether or not the statistical artifacts vary from study to study. It is also shown that using sample-size weighting may result in underestimation of the standard error of the mean uncorrected correlation when there are outlier sample sizes.