David, > > I am sure I am opening myself up to looking stupid, >> > > Or exposing a failure to read the help page.
Well no, and of course I did read the help pages as well as several introductions on Wilcoxon before posting, but as I said in my other post it is generally not at all clear, the distinction between difference between medians and median differences. I didn't find the help page all that enlightening, given that I came to them with a firm misconception about medians< and the dummy data sets I created to try and work out what might be going on, plus data sets I pulled from Wilcoxon tutorials gave differences in medians that matched the Wilcoxon median differences. Now that I realise that the Wilcoxon gives median differences, and how they are calculated, it all makes more sense. I realise the data are highly skewed, but what started out as a quick look to see what a Wilcoxon looked like with this data, became an all morning search through text books and google, together with experiments in R, to try and work out why I was getting this discrepancy in locations. I now know why. Thanks, Graham [[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.