Dear j.c.l.omms, The Anova() function in the car package can compute so-called "type-II" and "type-III" tests. When there are terms in the model that are marginal to others (such as main effects marginal to interactions), type-III tests are of questionable interest and have to be formulated carefully to test sensible hypotheses. As well, since glm() with no family argument fits a linear model with normal errors, it would be more usual in R to use lm().
Regards, John ------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of jeroenooms > Sent: July-04-08 6:37 PM > To: r-help@r-project.org > Subject: [R] set type of SS in anova() > > > When you use the 'general linear model' analysis in SPSS, the first result is > a table with all terms with F-tests and significance values for all IV's. It > uses http://joyx.joensuu.fi/~ek/anova/sstypes.txt SS Type III , which has > the advantage that the order in which the variables are added to the model > does not matter, and therefore it is relatively objective. > > I would like to reproduce this output in R. However, when using > anova(glm.object, test="F"), the F test shows "Terms added sequentially > (first to last)". Because of this, the F values and p values of the terms > depend on the sequence in which they were added. Eg: an anova() of > glm(a~b+c) will give other results than glm(a~c+b). > > How can I specify the SS type of an anova in R, so that i can reproduce the > exact results as that i got in SPSS? > -- > View this message in context: http://www.nabble.com/set-type-of-SS-in- > anova%28%29-tp18287076p18287076.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.
