Thanx for your answer. I don't have the book, but found something on
the web:
http://www.basic.northwestern.edu/statguidefiles/oneway_anova.html
and
http://en.wikipedia.org/wiki/Analysis_of_variance#Assumptions
Seems to be the same on both of the sites :-)
Is this, that was meant?
Thanx again,
Daniel
> 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
>
> --------------------------------------------------------------
>
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>
> --------------------------------------------------------------
> Christoph Buser <buser at stat.math.ethz.ch>
> 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
> >
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