search for: ss_effect

Dear alltogether, I am searching for a way to determine "effect size" in multi-level models by using lme(). Coming from Psychology, for ordinary OLS there are measures (for meta-analysis, etc.) like CohensD <- (mean_EG - mean_CG) / SD_pooled or (p)eta^2 <- SS_effect / (SS_effect + SS_error) I do not intend to lead a discussion of the usefulness of such measures as long as the standards of psychological journals (e.g. as defined by the APA) order them. However, I wondered how to determine measures of effect size in lme. Pinheiro&Bates (2000) do not touc...