This list is about R programming help, not statistics, although they do sometimes overlap. However, as this appears to be entirely a statistics issue, it really belongs on a statistics list like stats.stackexchange.com , not here.
Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Nov 28, 2017 at 6:00 AM, Francesc Pla Juncà <cesc....@gmail.com> wrote: > Thanks in advance for your help. > > I am running a repeated measures ANOVA in r. The same group undergoes to > four different treatment conditions. So, all individuals are treated with > treatments A, B, C and D in four different occasions. > Once I get a significant ANOVA, I first run a paired samples t-test using > the code: > > t.test(X1,X2,paired=TRUE) #being x1 the punctuation after treatment 1 and > x2 the punctuation after > treatment 2. > > After this, I run a Tukey posthoc test for repeated measures as stated in > gribblelab: > > require(nlme) > a1<-lme(x~factortmnt,random=~1|factorid/factortmnt,data=mydata) > print(anova(a1)) > > require(multcomp) > summary(glht(a1,linfct=mcp(factortmnt="Tukey"))) > > The fact is that once I get both results, there are some occasions in which > I get lower p values with Tukeys correction than in paired t-tests. > > How is it possible? Isn't Tukey more restrictive than paired t-tests? > > Cesc > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
