I believe the short answer to your question is no: I don't believe it's possible to get the exact same answer from 'lme' or 'lmer' as from 'aov' for your example.
Without a philosophical discussion, I can't tell you why. I almost never use 'aov', because it tests everything using an 'F' test, the particular 'F' is really relevant to what we want to know or not. With 'lme' and 'lmer', I have more confidence that I know what I'm doing and that I'm testing the hypotheses that are likely to be of greatest interest for my problem. The 'aov' algorithm was wonderful half a century ago, and was still the best procedure easily available to most people a quarter century ago. We have better tools available today. In case someone reading this reply wants more information on this, I suggest they start with the discussion of 'Conservative ANOVA tables in lmer' in the R Wiki. Hope this helps. Spencer Graves Rafael Laboissiere wrote: > First of all, I apologize for asking a question that has appeared > recurrently in this mailing list. However, I have googled for it, have > looked at the mailing list archives, and also looked at Pinheiro & Bates book > (although not very thoroughly, I must confess), to no avail. > > Here is the question: I am trying to obtain with lme or lmer the same exact > numerical results (p-values) that I obtain with aov. Consider the following > data: > > d <- data.frame (a = factor (rep (c (1, 2), c(10, 10))), > b = factor (rep (rep (c (1, 2), c(5, 5)),2)), > s = factor (rep (1 : 5, 4)), > v = rnorm (20)) > > Let us say that this comes from a repeated measures experiments where all > five subjects (factor s) were tested in all combinations of the two fixed > factors a and b. > > With aov, for a model were s, s:a, s:b and s:a:b are random, and a*b > are fixed terms, I would use: > > aov (v ~ a*b + Error (s / (a*b)), data = d) > > Is there a way to get the same results using lme or lmer? How should I write > my "random" argument in lme or the "(...|...)" terms in lmer? Please notice > that I am not interested in philosophical discussions about whether I am > trying to do wrong things. I would only like to know whether a given R > function could be used in place of another R function. > > Thanks in advance for your help, > > ______________________________________________ R-help@stat.math.ethz.ch 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.