[R] Significance test for discrete data

[Peter Dalgaard]

Christophe Pallier wrote:
> The Wilcoxon paired rank sign test assumes symmetry.
> (cf. http://www.basic.northwestern.edu/statguidefiles/srank_paired_alts.html
> )
>
>   
...of differences, and under the null hypothesis. This is usually rather
uncontroversial. With only 7 different outcomes for differences (-3:3)
you need to pay attention to ties, though. R's wilcox.test will get the
asymptotic variance right, but cannot do exact test in that case, so you
may want to check out package ExactRankTests.

> Christophe Pallier
>
> On 5/10/07, Alexander Kollmann <kollmann at telbiomed.at> wrote:
>   
>> Hello,
>>
>> given situation:
>>
>> - pre / post test comparison of discrete, paired data [values can be
>> 1,2,3,4].
>> - the data are neither normal distributed nor symetric
>>
>> Which test should I use to calculate the p-value? Is the wilcoxon rank sum
>> test ok ?
>>
>>
>> Alex
>>
>> ______________________________________________
>> R-help at 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.
>>
>>     
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.
>   


-- 
   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.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907