Re: [R] Preconditions for a variance analysis

From: Christoph Buser <buser_at_stat.math.ethz.ch>
Date: Wed, 20 Jun 2007 09:21:19 +0200

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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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. Received on Wed 20 Jun 2007 - 07:27:59 GMT

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