[R-sig-ME] random effects specification

Sebastian P. Luque spluque at gmail.com
Tue Apr 8 22:35:15 CEST 2008

[sorry for the line wrap mangling]

On Tue, 8 Apr 2008 21:47:04 +0200,
"Reinhold Kliegl" <reinhold.kliegl at gmail.com> wrote:


> You can reconstruct the table of means from the coefficients: A B a :
> intercept intercept + communityB b: intercept + treatmentb intercept +
> treatmentb + communityB + communityB:treatmentb c: intercept +
> treatmentc intercept + treatmentc + communityB + communityB:treatmentc
> d: intercept + treatmentd intercept + treatmentd + communityB +
> communityB:treatmentd

Yes, but IIUC, this is not necessarily equivalent to fitting separate
models with subsets of the terms/levels.  Correct me if I'm wrong, but I
think the estimates will differ when the design is unbalanced (e.g. some
subjects not receiving all treatments) because a straight calculation
from the full model assumes the coefficients have equal weight.  For
this example data, the design is balanced, so this might not be a


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