[R] Wilcoxon Rank test

[Wolfgang Huber]

Dear Omar,

the p-value is the probability that a certain summary statistic U of the 
data takes the value it takes, given that the null-hypothesis is true. 
Your p-value is 0.002, you can compare this to an alpha of your choice, 
and if that alpha were larger, you would come to the decision that the 
null-hypothesis can be rejected.

Best wishes
   Wolfgang

------------------------------------------------------------------
Wolfgang Huber  EBI/EMBL  Cambridge UK  http://www.ebi.ac.uk/huber


  Baqueiro ha scritto:
> Greetings, I am trying to perform a Mann-Whitney U test to a pair of
> data series, according to what I have read about R the command to use
> is:
> 
> wilcox.test(data1, data2)
> 
> However I am having trouble interpreting the results:
> ---
> Wilcoxon rank sum test with continuity correction
> 
> data:  Dataset$OTMinR and Dataset$OTMaxW
> W = 460627.5, p-value = 0.001798
> alternative hypothesis: true location shift is not equal to 0
> ---
> 
> According to my understanding the test tests the hypothesis that  the
> two data series are drawn from a single population. And I interpret
> those results, having the p-value 0.001798, that the hypothesis is NOT
> rejected, meaning that there is a high probability that the two
> samples come from the same population. Is that interpretation true?
> 
> Also, I am not sure what is the alpha value of the performed test? is
> it 0.05? or 0.01? is there a way to change it?
> 
> Thank you!
>