Dear Paul, > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of pgseye > Sent: January-29-09 10:07 PM > To: r-help@r-project.org > Subject: Re: [R] Q about how to use Anova.mlm > > > Thanks a lot for that John - really helpful. I generated some random numbers > and seem to be able to get it to work, so that's great. > > One thing - it's come up with a 'Type III' test and given me a few warnings. > What's the difference between Type II and Type III tests (if there's some > basic guide you can point me to).
The default for Anova() is "type-II" tests, but the computational approach taken doesn't provide a test for the intercept, which is the only between-subject term in the model; thus, a "type-III" test is substituted. In a model with only an intercept, there is no distinction between the two "types" of tests. More generally, types II and III tests address different hypotheses in models in which some terms are marginal to others. There's a brief explanation in my R and S-PLUS Companion to Applied Regression (Wiley, 2002), which is the book associated with the car package in which Anova() resides. There's a more complete discussion in my Applied Regression Analysis and Generalized Linear Models, Second Edition (Sage, 2008). Neither book, BTW, discusses repeated-measures models. I hope this helps, John > > Thank you again. > > Best, > > Paul > > -- > View this message in context: http://www.nabble.com/Q-about-how-to-use- > Anova.mlm-tp21739443p21740704.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.
