Rosenthal, RobertRubin, Donald2014-02-191982Rosenthal, Robert. 1982. "Comparing Effect Sizes of Independent Studies." Psychological Bulletin 92, No. 2: 500-504.0033-2909http://nrs.harvard.edu/urn-3:HUL.InstRepos:11718224This article presents a general set of procedures for comparing the effect sizes of two or more independent studies. The procedures include a method for calculating the approximate significance level for the heterogeneity of effect sizes of studies and a method for calculating the approximate significance level of a contrast among the effect sizes. Although the focus is on effect size as measured by the standardized difference between the means (d) defined as (Mi — M-^/S, the procedures can be applied to any measure of effect size having an estimated variance. This extension is illustrated with effect size measured by the difference between proportions.en-USJournal Article2014-01-29Rosenthal, Robert10.1037//0033-2909.92.2.500