"Jack Tanner" <[EMAIL PROTECTED]> writes: > From: Rolf Turner <[EMAIL PROTECTED]> > >No. The pairwise.t.test() function (according to the help > >file) does a multiplicity of t-tests, on more than two > >samples, adjusting the p-value to compensate for the > >multiplicity by various methods. > > Thank you, Rolf, that's helpful. So pairwise.t.test() is used for > comparison of more than two means. I did, indeed, confuse it with > t.test(paired=TRUE). But the documentation, which I valiantly tried to > make sense of BEFORE asking my stupid question, is not clear enough > for this particular idiot. Might I suggest that the documentation be > altered? It could use an example (as in, real-life applied statistical > problem) of when pairwise.t.test() ought to be used, and why > t.test(paired=TRUE) would be inappropriate in that context; it could > also use a reference to some published paper, website or some such > that explains the rationale and correct procedure for using this test. > > Thanks again for your clairvoyance.
I didn't suggest looking at the example section of the help pages without a reason... It should be pretty clear example(pairwise.t.test) does give output that pretty clearly indicates that all pairwise comparisons are being performed. We do have a bug though: in 1.9.1 print.pairwise.htest seems to have gone AWOL, so that the pretty-printing is not as nice as it might have been. (And it might also be called a buglet that there's no example with a paired t test.) -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
