Re: [R] glmmPQL model selection

From: Ben Bolker <>
Date: Tue 21 Feb 2006 - 02:38:42 EST

Emmanuelle TASTARD <tastard <at>> writes:

> Hi,
> I’m sorry, I know that it is a recurrent question but I have not been
> able to find the response in the Rhelp archives.
> I think my data require the use of the glmmPQL function but I do not
> know how to make the model selection. Since the AIC and log-likelihood
> are apparently meaningless, how can we select the parameters for a model
> and compare the models to find which one fits best the data?

  I think your choices are (1) use the estimated standard errors/p-values of the fixed effects to decide whether to include them in the model or (2) if you really need likelihood-based tests, use lmer. (Model selection for variance parameters is a can of worms, see Pinheiro and Bates.) Also remember that *all* methods for this kind of model are approximations, it's just a question of which ones are more accurate (generally and in particular situations).

That's just my best guess, someone else may have better advice ...

     Ben Bolker mailing list PLEASE do read the posting guide! Received on Tue Feb 21 02:50:29 2006

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