And if I decided to ignore the "type" variable altogether and simply use the continuous "valence" variable, this is what I'd use?
summary(lme( fixed = rt~valence*color , data = a ,random = ~1|id )) I also have continuous luminance measurements of each color that vary from participant to participant (we used different monitors). If I were interested in luminance *instead* of color, would the following be appropriate, or do I need to do something special to account for the fact that each participant has different values of luminance? summary(lme( fixed = rt~valence*luminance , data = a ,random = ~1|id )) On Sat, Feb 7, 2009 at 12:34 PM, Dieter Menne <dieter.me...@menne-biomed.de> wrote: > Mike Lawrence <mike <at> thatmike.com> writes: > >> >>Would it improve things if "type" were a continuous variable rather >>than categorical? I chose words at the extreme ends of a valence >>rating scale but I still have the raw valence ratings for each word. >> >> > >> > With the interaction, the extreme would be >> > summary(lme(rt~type*color*word, data=a,random=~1|id)) >> > >> > or, less extreme >> > >> > summary(lme(rt~type*color+color:word, data=a,random=~1|id)) > .. > Something like > > summary(lme(rt~type*color+color:as.numeric(word), data=a,random=~1|id)) > > (please replace as.numeric() by the raw valence, the example above it > simply wrong) > > could gain you a few degrees of freedom if you are willing to accept the > linear hypothesis. And as there is something like raw valence, one should > not throw away details about a-priori ordering in favor of a categorical > hypothesis. > > Dieter > > ______________________________________________ > 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. > -- Mike Lawrence Graduate Student Department of Psychology Dalhousie University www.thatmike.com Looking to arrange a meeting? Check my public calendar: http://www.thatmike.com/mikes-public-calendar ~ Certainty is folly... I think. ~ ______________________________________________ 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.