Partialing out the effect of a covariable in a Poisson GLMM

<v_coudrain at ...> writes:

Dear all,
I recenly asked a question about the use of an offset in a Poisson GLMM 
and it came out that an ofset would be
reasonable if the estimate of the covariable to be put 
as an offset is about 1. However if this estimate is not close 
to one, does anybody know about a partial linear
regression equivalent for a Poisson GLMM? Or what 
are your method to control for the effect of a covariable in a Poisson GLMM?

Don't know exactly what you want to do, but presumably fitting
a "null model" with the covariate and then building more complex models
on top of this -- adding the other covariates -- and doing sequential testing
(anova(full_model,model_with_only_first_covariate)).  The linear models
idea of partialing out one variable and running a model on the residuals
doesn't work as well, unfortunately.

  Ben Bolker