Abstract: | The behavior of the L. V. Hedges's (see record 1983-00213-001) Q test for the fixed-effects meta-analytic model was investigated for small and unequal study sample sizes paired with larger numbers of studies, nonnormal score distributions, and unequal variances. The results of a Monte Carlo study indicate that the hypothesis of equal effect sizes tends to be rejected less than expected if smaller study sample sizes are paired with larger numbers of studies; pairing smaller variances with larger sample sizes (or vice versa) leads to this hypothesis being rejected more than expected. The power of the Q test is also less than expected when small study sample sizes are paired with larger numbers of studies. These findings suggest conditions for which the Q test should be used cautiously. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |