[R] permutation test assumption?

[João Fadista]

Dear Thierry,
 
Thanks for the reply. But as you may read in the paper http://bioinformatics.oxfordjournals.org/cgi/content/abstract/22/18/2244 when the sample sizes are not the same there may be an increase in the Type I error rate.
 
Comments will be appreciated.
 
Best regards,
João Fadista
 

________________________________

De: ONKELINX, Thierry [mailto:Thierry.ONKELINX at inbo.be]
Enviada: ter 08-04-2008 15:27
Para: João Fadista; r-help at r-project.org
Assunto: RE: [R] permutation test assumption?



Dear João,

You can do permutation tests on an unbalanced design.

HTH,

Thierry


----------------------------------------------------------------------------
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance
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9500 Geraardsbergen
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tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
www.inbo.be

To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey

-----Oorspronkelijk bericht-----
Van: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Namens João Fadista
Verzonden: dinsdag 8 april 2008 15:18
Aan: r-help at r-project.org
Onderwerp: [R] permutation test assumption?

Dear all,

Can I do a permutation test if the number of individuals in one group is much bigger than in the other group? I searched the literature but I didin´t find any assumption that refers to this subject for permutation tests.


Best regards

João Fadista
Ph.d. student


       
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