Thanks Richard, I tried running the analysis the way you suggested but here is the error that I get
> track.aov <- aov(mice ~ coon+block*veget*fruit*time - > block:veget:fruit:time + + Error(block/plot), data = track) Warning message: In aov(kotz.mice ~ kotz.coon + block * veget * fruit * time - block:veget:fruit:time + : Error() model is singular > anova(track.aov) Error in UseMethod("anova") : no applicable method for "anova" I'm not sure you can use the function anova for an aov object. I tried summary and it also didn't work. Did you mean something else? Thanks Richard M. Heiberger wrote: > > track.aov <- aov(mice ~ coon > + block*veget*fruit*time - block:veget:fruit:time > + Error(block/plot), data = track) > anova(track.aov) > > > I think this is what you are looking for. This model in words says, > What is the effect of the four-way crossing after adjusting for > the covariate coon? We don't have enough degrees of freedom for > the full crossing, so remove the four-way interaction. > > anova() gives the sequential sums of squares of (multi-degree of > freedom) effects. Be sure that the five variables (block, veget, fruit, > time, plot) are factors. I am assuming time is a factor here. > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/ANCOVA-with-defined-error-terms-tp25055311p25061223.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.