Dear Sam, I don't think that you can use the Anova() function in the car package for this design because there would be no way to specify the error term.
Sorry, John -------------------------------- John Fox Senator William McMaster Professor of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] > On Behalf Of Sam Chand > Sent: May-20-11 11:15 PM > To: r-help@r-project.org > Subject: [R] unbalanced anova with subsampling (Type III SS) > > Hello R-users, > I am trying to obtain Type III SS for an ANOVA with subsampling. My > design is slightly unbalanced with either 3 or 4 subsamples per > replicate. > > The basic aov model would be: > fit <- aov(y~x+Error(subsample)) > > But this gives Type I SS and not Type III. > > But, using the drop() option: > drop1(fit, test="F") > > I get an error message: > "Error in UseMethod("extractAIC") : no applicable method for > "extractAIC" > > Changing the "contrasts" to "contr.helmert", "contr.poly" also does > not help. > > Can I use library(car) for unbalanced subsamples? > > I am very confused. > Any help would be greatly appreciated. > -Sam > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.