On Thu, 19 Aug 2004 13:42:21 -0300 (ADT), Rolf Turner <[EMAIL PROTECTED]> wrote :
> >You wrote: > >> What's the difference between t.test(x, y) and pairwise.t.test()? Is >> it just that the former takes two vectors, whereas the latter takes a >> vector and a factor? > > 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. > > IMHO the name of this function is bad, because to me it > suggests doing ***paired*** t-tests, which would trip up the > naive user, who probably wouldn't notice or would ignore the > "t tests with pooled SD" message in the output. As one of > the Ripley fortunes says ``It really is hard to anticipate > just how silly users can be.'' But why go out of the way to > give them a chance to be silly? And Jack wrote: >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. I think it's unlikely that we would rename the function; it's been around a while with its current name so that's a bad idea. On the other hand, clearer documentation is always a plus: why not submit some? Duncan Murdoch ______________________________________________ [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
