Apples and Oranges (and Pears, Oh My!): The Search for Moderators in Meta-Analysis

The purpose of this article is to review current practices with respect to detection and estimation of moderators in meta-analysis and to develop recommendations that are driven by the results of this review and previous research. The first purpose was accomplished through a review of the meta-analyses published in Journal of Applied Psychology from 1978 to 1997. Results show, first, that practices with respect to both the execution of and the reporting of results from searches for moderators are highly variable and, second, that findings relevant for detection of moderators (e.g., percentage variance attributable to artifacts, SDρ, etc.) are often highly inconsistent with what has been suggested in the past. These practices held regardless of time of publication, specificity of the question addressed in the paper, and content area. Detailed suggestions for modifications of current practices are offered.