Sorry, that in the last message the tables were messed up. Here is a link to the tables http://www-scf.usc.edu/~hex/data.txt
<http://www-scf.usc.edu/~hex/data.txt>Thanks! On Sun, Jun 6, 2010 at 10:18 AM, Xiao He <praguewaterme...@gmail.com> wrote: > Dear R people, > > I have a couple of questions about post-doc analyses for 2 by 2 within > subjects ANOVA. I conducted a psycholinguistic study that combined a 2 by 2 > design and a latin square design. Specifically, I had 32 items each of which > generated 4 conditions. Participants saw each of the 32 items only once: 8 > in Condition A, 8 in B, 8 in C, and 8 in D. The table below serves as an > example. > > *Subject* *Factor1* *Factor2* *Condition* *ReadingTime* *Item* 1 A A A 238 > Item1 1 A A A 369 Item5 1 A A A 494 Item9 *.* *.* *.* *.* *.* *.* *.* *.* > *.* *.* *.* *.* 1 B A C 294 Item22 1 B A C 694 Item26 *.* *.* *.* *.* *.* > *.* *.* *.* *.* *.* *.* *.* 8 A A A 334 Item3 8 A A A 366 Item7 *.* *.* *. > * *.* *.* *.* *.* *.* *.* *.* *.* *.* > > I did ANOVA by using the following > : > result.subject=aov(ReadingTime~Factor1*Factor2 + > Error(Subject/(Factor1*Factor2)), data=data), AND > result.item=aov(ReadingTime~Factor1*Factor2 + > Error(Item/(Factor1*Factor2)), data=data). > > > Both both functions returned significances. Now I am confused as to what > methods I should use to do post-hoc analysis and how to use them. I > attempted TukeyHSD, but it gave me an error message as shown below. I am not > sure how to apply TukeyHSD properly since the help file was not clear enough > on that. So I wonder if you can tell me what went wrong with my function. > > > TukeyHSD(result.subject, c('Factor1','Factor2'), ordered=TRUE) > Error in UseMethod("TukeyHSD") : > no applicable method for 'TukeyHSD' applied to an object of class > "c('aovlist', 'listof')" > > Also, I I attempted *pairwise.t.test* by averaging each participant's > reading times in each condition (see the table below) with *p* values > adjusted with Bonferroni method (*e.g. *pairwise.t.test(y,group, > "bonferroni", pair=TRUE)), . It gave me significant results. But I am not > sure if it is a proper method to use (Sorry I know this is more of a > statistics related problem). So I wonder if you can tell me if > pairwise.t.test is a proper method. If not, what other functions might be > useful for post-hoc analysis. Thank you in advance!! > > *Subject* *Condition* *AvgRT* 1 A 210 2 A 309 . . . . . . 19 A 305 20 A > 502 1 B 480 2 B 209 . . . . . . 19 B 400 20 B 270 . . . . . . 19 D 190 20 D > 254 > > [[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.
