In pretest-posttest nonequivalent group designs, naive use of analysis of covariance or
multiple regression can lead to Type I errors. In the evaluation of a Title IV-C, ESEA
project, thorough analysis of the interaction term of a repeated model analysis of variance
was shown to help identify areas of significant change. Meaningful differences were also
supported by the standardized difference score, Effect Size. It was suggested that a
two-fold increase of Effect Size from pretest to posttest might be an effective guide in the
determination of meaningfully significant change.
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