Dear Mattune, I guess that you're using the effect() function in the effects package. You've requested the effect for the covariate fixing the values of the factors, rather than vice-versa. Try effect("a*b*c", Anocova.Model) or, for more detail in the output, summary(effect("a*b*c", Anocova.Model)). I assume, BTW, that you fit the model X ~ a*b*c + d, with d the covariate, rather than what you said you did.
I hope this helps, John -------------------------------- John Fox Senator William McMaster Professor of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Mattune > Sent: October-17-11 3:45 PM > To: r-help@r-project.org > Subject: [R] Adjusted Means > > I'm running the following ANCOVA model in R: X=a*b*d + d where d is the > covariate. I want to produce adjusted means for X for all possible treatment > combinations. a has 6 levels, b has 2 levels, c has 2 levels, so this is a > 6x2x2 = 24 possible treatment combinations. When I run: > effect("d", Ancova.Model) I am given only 20 adjusted means (also, I'm not > exactly sure of how the adjusted means are reported, that is, which one > represents which treatment combination...what order are they in?) Any > ideas?? > > Thanks! > Master's Student in Maine > > -- > View this message in context: http://r.789695.n4.nabble.com/Adjusted-Means- > tp3913159p3913159.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. ______________________________________________ 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.