Dear David Yes. There are assumptions that should be verified in an analysis of variance. Without checking them, the results are not reliable. I'd recommend e.g.
Robert O. Kuehl, Design of Experiments: Statistical Principles of Research Design and Analysis, Duxbury Press, 2000 You will find a chapter about assumptions and how to check them by residual analysis, And also W. N. Venables and B. D. Ripley, Modern Applied Statistics with S, Springer-Verlag, New York, 2002 in which you find residual analysis and how to obtain it in R. Best regards, Christoph -------------------------------------------------------------- Credit and Surety PML study: visit our web page www.cs-pml.org -------------------------------------------------------------- Christoph Buser <[EMAIL PROTECTED]> Seminar fuer Statistik, LEO C13 ETH Zurich 8092 Zurich SWITZERLAND phone: x-41-44-632-4673 fax: 632-1228 http://stat.ethz.ch/~buser/ -------------------------------------------------------------- Daniel Tahin writes: > Hello everbody, > > i'm currently using the anova()-test for a small data.frame of 40 > rows and 2 columns. It works well, but is there any preconditions for > a valid variance analysis, that i should consider? > > Thank you for your answer, > Daniel > > ______________________________________________ > 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 > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.
