Implications of direct and indirect range restriction for meta-analysis methods and findings.

Range restriction in most data sets is indirect, but the meta-analysis methods used to date have applied the correction for direct range restriction to data in which range restriction is indirect. The authors show that this results in substantial undercorrections for the effects of range restriction, and they present meta-analysis methods for making accurate corrections when range restriction is indirect. Applying these methods to a well-known large-sample empirical database, the authors estimate that previous meta-analyses have underestimated the correlation between general mental ability and job performance by about 25%, indicating that this is potentially an important methodological issue in meta-analysis in general.