METAANALYSIS OF EXPERIMENTS WITH MATCHED GROUPS OR REPEATED-MEASURES DESIGNS

Tests for experiments with matched groups or repeated measures designs use error terms that involve the correlation between the measures as well as the variance of the data. The larger the correlation between t he measures, the smaller the error and the larger the test statistic; If an effect size is computed from the test statistic without taking t he correlation between the measures into account, effect size will be overestimated. Procedures for computing effect size appropriately from matched groups or repeated measures designs are discussed.