Magnitude of Gender Differences
The distribution of effect sizes was approximately normal and
centered around zero. The overall analysis of effectiveness measures
resulted in a mean corrected d of .05 (K 99, N
101,676), which is not significantly different from zero (see Table
1). We examined the data for any extreme outliers (3 SD) and
found two effect sizes that met this criteria (d 1.44, N 30 and
d 1.52, N 40). Hunter and Schmidt (2004) argued that, when
sample sizes of outliers are small to moderate, extreme outliers can
occur due to sampling error. They noted that such outliers should
not be removed from the data, because removing them could result
in an overcorrection of sampling error.