Hi, I would like to run an ANOVA with repeated measures with both a between subjects variable and within subjects (repeated measures) variables. I know how to do this when I have equal numbers of subjects in both groups (i.e., balanced design). That has been very well documented by Baron, for example, see:
http://cran.r-project.org/doc/contrib/Baron-rpsych.pdf On page 34 of this document, section 6.8.5, Baron & Li example wonderfully how to run a 'balanced' ANOVA with one between and two within subject varialbes (6.8.5 Example 5: Stevens pp. 468 – 474 (one between, two within)). The R code in their example is: summary(aov(effect ̃ gp * drug * dose + Error(subj/(dose+drug)), data=Ela.uni)) The between subjects variable is gp, whereas drug and dose are within subject variables. Now, my question is, how would I do this very same analysis if there were *different* numbers of subjects in the groups (that is, 'unbalanced')? Clearly, the 'aov' function is not appropriate for this! (help(aov) says: 'aov' is designed for balanced designs, and the results can be hard to interpret without balance) I have found suggestions that this problem might be solved with the 'lme' function of the 'nlme' library, but it is entirely unclear to me how and I could not find an answer anywhere in the r forums. Thank you so much for your help. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
