This paper describes how work by the United States Office of Personnel Management on the generalizability of employment test validities led to the development of a widely applicable meta-analysis method. The method focuses strongly on estimating the true variance of study correlations and effect size. This validity generalization procedure has…

Since meta-analysis was described in 1976 (Glass) as the application of familiar experimental methods to the integration of available research, at least five coherent approaches to meta-analysis have appeared in common use. These approaches can be divided into two broad groups. In the first group (including procedures by Robert Rosenthal, Larry…

Drawing from work on the meta-analysis of over 500 validation studies of the General Aptitude Test Battery (GATB) by the U.S. Employment Service, the paper presents a methodological message and a substantive message. Gene Glass's methods, as used by Edwin Ghiselli in personnel selection, ignore study artifacts (sampling error, error of…

Statistical methodologists have sometimes criticized the use of conventional statistics in meta-analysis, and in recent years a number of them have advocated the use of a special new statistical methodology for research synthesis. An examination of recent books describing this methodology shows that it is seriously limited in its applicability to…