[R] ANCOVA with defined error terms

Richard M. Heiberger rmh at temple.edu
Thu Aug 20 17:01:00 CEST 2009

Yes, I meant summary().  anova() isn't defined for aovlist objects and 
summary() is.
> Warning message:
> In aov(kotz.mice ~ kotz.coon + block * veget * fruit * time -
> block:veget:fruit:time +  :
>   Error() model is singular

You will need to investigate the singular Error() model.  You might want
to use the simpler Error model


My guess is the plot term is redundant.

What are kotz.mice?  That variable isn't in the model you showed.

For more detailed help you will need to
"provide commented, minimal, self-contained, reproducible code."


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