The meta-analysis of partial effect sizes.

This paper discusses the synthesis of partial effect sizes derived from multivariate settings. The general statistical properties of the d-effect size are derived, extending Hedges's statement of zero-order properties. These general properties have direct relevance in the synthesis of a set of independent effect sizes arising from empirical studies predicated on a common theoretical model. We discuss possible solutions to the problem of comparing effect sizes arising from models employing differing sets of covariates. We apply the general statistical properties in the synthesis of gender performance differences in first-level economics courses at three New Zealand universities. The model of academic performance is based on Spearman's conception of general academic ability and specific ability in economics.