Regression Models in Research Synthesis

Abstract The extensive research literature in many areas of behavioral, medical, and social sciences has led some reviewers to the use of quantitative methods for research synthesis. Typically, these analyses have involved estimating the effect magnitude from each of a series of studies and averaging the estimates to obtain a single index of effect magnitude. This article provides some statistical methods for estimating and testing linear models for effect magnitude and can be used for determining the effect of variations in experimental conditions. These methods can be used for synthesizing the results of studies where the index of effect magnitude is a correlation coefficient or standardized mean difference. A natural test for model specification is also given.