Thomas Lumley wrote: > On Thu, 11 Feb 2010, Protzko wrote: > >> >> I guess my subject says it all. But I loaded a dataset in spss and >> used the >> foreign package to read and save it in R. Running an anova (using the >> aov >> command) gives a different F and p value in R than it does in SPSS. ANy >> idea what is going on? > > Yes. Either you specified a different model or different tests for the > same model in the two systems, or you are interpreting the output > incorrectly, or the results are different.
Also beware of unbalanced data sets, aov() will not handle Error() terms properly in an unbalanced design, and in general tests will be order dependent (type 1 tests in SAS terminology). > > Without more detail it is hard to be sure, but the first two > possibilities seem more likely. Yes, many people on the list can probably spot the issue when seeing the two anova tables. > > -thomas > > Thomas Lumley Assoc. Professor, Biostatistics > tlum...@u.washington.edu University of Washington, Seattle > > ______________________________________________ > 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. -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalga...@biostat.ku.dk) FAX: (+45) 35327907 ______________________________________________ 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.
