The purpose of this study was to compare the results of the Hunter-Schmidt meta-analytic technique with the results of the Glass meta-analytic technique on three meta-analytic data sets chosen from the education literature. The hypothesis investigated was that the Hunter-Schmidt mean effect size would be significantly larger than the Glass mean effect size because of the correction for measurement error. In two out of three data sets, the Hunter-Schmidt mean effect size (p < .05). These results suggest that the correction for unreliability in the measures did have an impact on the effect sizes.
Abstract