Yes, but ... the original poster said the coefficients differed too. (The blog post you refer to deals with ANOVA (i.e. linear models) rather than GLMs (generalized linear models): it is true that the sequential/marginal distinction still applies, but I don't think that can be the *only* thing going on here.)
On Fri, Aug 13, 2010 at 10:50 PM, Martin Teicher <martin_teic...@hms.harvard.edu> wrote: > R usesType I sequential SS, not the default Type III marginal SS reported by > SPSS. There is a good blog post explaining this difference along with some > interesting comments -- > http://myowelt.blogspot.com/2008/05/obtaining-same-anova-results-in-r-as-in.html > > Best Wishes, > > Martin H. Teicher > Dept of Psychiatry > McLean Hospital / Harvard Medical School > Belmont MA 02478 > > > On Aug 13, 2010, at 10:32 PM, Ben Bolker wrote: > >> Leo Vorthoren <L.Vorthoren <at> nioo.knaw.nl> writes: >> >>> I have been using generalized linear models in SPSS 18, in order to build >>> models and to calculate the P values. When I was building models in Excel >>> (using the intercept and Bs from SPSS), I noticed that the graphs differed >>> from my expectations. When I ran the dataset again in R, I got totally >>> different outcomes for both the P values as well as the Bs and the >>> intercepts. The outcomes of R seem much more likely to be the correct ones, >>> but I really cannot explain the differences. >> >> I appreciate/assume that you're asking on the off chance that someone >> else has tried something very similar and gone to the trouble of figuring >> out the differences between R's and SPSS's default setup, but you're >> unlikely to get an answer without more detailed information. >> >> My best guess is that SPSS and R are using different contrasts >> and/or different baseline levels. R uses treatment contrasts by default, >> and assumes that the first (alphabetical) level of a factor is the >> baseline level. >> >> It's conceivable that you have a dataset where the results are >> numerically unstable and sensitive to small details in the algorithms >> used. >> >> ______________________________________________ >> 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.
