You can do a transformation on your Y, and than use the normal tools. Using something like a median test is not advisable due to low power, and a wilcox.test is considered a better choice (although the meaning is more complex when observations are not symmetrically distributed).
If you wish to perform a one way anova, which is non parametric, you can use: ?kruskal.test And after that you can use the tools suggested here by David Winsemius<http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=user_nodes&user=4999> : http://r.789695.n4.nabble.com/post-hoc-test-with-kruskal-test-td898661.html With regards, Tal ----------------Contact Details:------------------------------------------------------- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) ---------------------------------------------------------------------------------------------- On Thu, Jul 19, 2012 at 11:14 PM, Data Analytics Corp. < w...@dataanalyticscorp.com> wrote: > Hi, > > A client has a consumption measure on each of four products. The sample > size is 75. The consumption distributions are highly skewed for each > product. He would like a pairwise comparison test of the products, much > like Tukey's HSD but using medians rather than means. Is there such a > median comparison test in R? > > Thanks, > > Walt > > ________________________ > > Walter R. Paczkowski, Ph.D. > Data Analytics Corp. > 44 Hamilton Lane > Plainsboro, NJ 08536 > ________________________ > (V) 609-936-8999 > (F) 609-936-3733 > w...@dataanalyticscorp.com > www.dataanalyticscorp.com > > ______________________________**________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> > PLEASE do read the posting guide http://www.R-project.org/** > posting-guide.html <http://www.R-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.
