Indeed, but are not each of the cell means also evaluations of the effect of one factor at the specific level of another factor? Is this an issue of "Tomato, tomahto".
I guess my question is, if I want to know if each of those is different from 0, then should I use the 48df from the full model, or the 9 for each cell? Chuck Cleland wrote: > > That does not corresponds to what I think of as the simple effects. > That specifies the six cell means, but it does not *compare* any cell > means. I think of a simple effect as the effect of one factor at a > specific level of some other factor. > >> summary(glht(fm, linfct = cm2), test = adjusted(type="none")) >> >> Correct? What is the df on those t-tests then? Is it 48? > > Yes, df = 48 for each contrast. > >> Interestingly, I find this produces results no different than >> >> fm2<-lm(breaks ~ tension:wool+0, data=warpbreaks) >> summary(fm2) > > Yes, but those are not what I would call the simple effects. Those > are essentially one-sample t-tests for each of the 6 cell means. > >> Also, here, it would seem each t-test was done with the full 48df. Hrm. > > The df are based on the whole model, not the 9 observations in one > cell. > > > -- View this message in context: http://www.nabble.com/Asking%2C-are-simple-effects-different-from-0-tp15835552p15857771.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
