I suggest you consult a local statistician or read up on linear models,perhaps by reading the relevant section of V&R's MASS. Also search the R-Help archives for "Type III SS." Further comments below.
-- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA "The business of the statistician is to catalyze the scientific learning process." - George E. P. Box > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Martin Julien > Sent: Tuesday, January 17, 2006 12:34 PM > To: r-help@stat.math.ethz.ch > Subject: [R] Anova problem with order of terms in model > > Hi > I have a linear model and I want to tests whether the model terms are > significant > I used anova but F and P value depend on the order of the terms in the > model. Correct. Differennt hypotheses are being tested. R does **sequential** SS (this preserves additivity/orthogonality of contrasts being tested). In a non-orthogonal designs, these depend on order. > I have repeated the same analysis in another stat software > and F and P value > did not differ with order of terms in the model. > Can anyone can explain what happen or what am I doing wrong ? And this "other software" is not doing a sequential SS, but rather what is usually called Type III SS (google on "Type III SS" for more info). ______________________________________________ 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