Thanks Torsten! I got it! Best, Baoqiang
---- Original message ---- >Date: Wed, 8 Nov 2006 17:26:18 +0100 (CET) >From: Torsten Hothorn <[EMAIL PROTECTED]> >Subject: Re: [R] interprete wilcox.test results >To: Baoqiang Cao <[EMAIL PROTECTED]> >Cc: r-help@stat.math.ethz.ch > > >On Wed, 8 Nov 2006, Baoqiang Cao wrote: > >> Dear All, >> >> I am using wilcox.test to test two samples, data_a and data_b, earch sample >> has 3 replicates, suppose data_a and data_b are 20*3 matrix. Then I used the >> following to test the null hypothesis (they are from same distribution.): >> >> wilcox.test(x=data_a, y=data_b, alternative="g") >> I got pvalue = 1.90806170863311e-09. >> >> When I switched data_a and data_b by doing the following: >> wilcox.test(x=data_b, y=data_a, alternative="g") >> I got pvalue = 0.999999998111886. >> >> I suppose because I am test them with same null hypothesis, > >no, you don't: > >H_0: mean(data_a) <= mean(data_b) (alternative = "greater") > >is different from > >H_0: mean(data_b) <= mean(data_a) > >check > >wilcox.test(x=data_a, y=data_b, alternative="l") > >Torsten > >> I should get same result (pvalue). Since I am not a savy statistician at >> all, maybe that is a wrong assumption, could anyone please point out the >> right interpretion please? >> >> Thanks! >> >> Best, >> Baoqiang >> >> ______________________________________________ >> R-help@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. >> >> ______________________________________________ R-help@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.