Re: [R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-24 Thread Bert Gunter
Andrew Gelman's "Working Through Some Issues" and the two Letters to the Editor that follow responding to the editorial decision to ban P values from The Journal of Basic and Applied Social Psychology (BASP). You may wish also to read ASA President's David Morgenstern's reflexive and entirely predi

Re: [R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-24 Thread Jeff Newmiller
Bert, can you be more specific about which article for those of us who don't subscribe? --- Jeff NewmillerThe . . Go Live... DCN:Basics: ##.#. ##.#. Live Go...

Re: [R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-24 Thread Denis Chabot
Thank you, Thierry. And yes, Bert, it turns out that it is more of a statistical question after all, but again, since my question used specific R functions, R experts are well placed to help me. As pairewise.t.test was recommended in a few tutorials about repeated-measure Anovas, I assumed it t

Re: [R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-24 Thread Bert Gunter
I would **strongly** recommend that you speak with a local statistical expert before proceeding further. Your obsession with statistical significance is very dangerous. (see the current issue of SIGNIFICANCE for some explanation). Cheers, Bert Bert Gunter "Data is not information. Information is

Re: [R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-23 Thread Bert Gunter
Yours is (primarily) a statistical question, not a question about R, and so off topic here. Post on a statistics list, like stats.stackexchange.com instead. Better yet, consult a local statistician. This is a thorny and difficult matter and, as you have already discovered, is "full of sound and fur

Re: [R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-23 Thread Thierry Onkelinx
Dear Denis, It's not multcomp which is too conservative, it is the pairwise t-test which is too liberal. The pairwise t-test doesn't take the random effect of Case into account. Best regards, ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest te

[R] repeated measures: multiple comparisons with pairwise.t.test and multcomp disagree

2015-06-22 Thread Denis Chabot
Hi, I am working on a problem which I think can be handled as a repeated measures analysis, and I have read many tutorials about how to do this with R. This part goes well, but I get stuck with the multiple comparisons I'd like to run afterward. I tried two methods that I have seen in my readin