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 touch that topic. I assume that as long as a grouping structure is present, the formular of CohensD (see above) has to be corrected to give respect to the grouping structure. Is there any equivalent measure like eta^2, partial-eta^2, etc.? Can anybody help me with formulas, R code or some references? Thank you very much, thanks in advance, leo gürtler -- email: [EMAIL PROTECTED] www: http://www.anicca-vijja.de/ ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
