Multiple methods—the chi-square-based Q statistic and the 75%
rule—were used to assess for the need to test for moderators.
Categorical moderator variables were examined with subgroups
analyses, and continuous moderators (percentage of male raters
and time of study) were examined with meta-analytic regression
analyses. Calculating the categorical models results in the
between-class goodness-of-fit statistic Qb, which is equivalent to a
main effect in an analysis of variance and indicates whether the
categorical moderator fully explains variance in the data (Cortina,
2003).