[R] Wilcoxon rank sum in unbalanced design

[peter dalgaard]

On Apr 13, 2011, at 17:07 , netrunner wrote:

> Hi everyone!
> I need to perform a Wilcoxon rank sum test, but I have some ties and the
> groups have different size also. When I deal with ties I use the
> wilcox.exact function, how can I solve the different size problem using this
> function? 

What problem? Wilcoxon tests work quite happily with unequal group sizes. There's some loss of power due to imbalance, but the only way around _that_ is to move observations from one group to the other...

(And exact testing actually solves a slightly different problem than the tie issue, but never mind.)

> 
> thanks
> 
> net
> 
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-- 
Peter Dalgaard
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com