On Wed, Feb 27, 2013 at 4:31 PM, Ben Bolker <bbolker@gmail.com> wrote:

>  <juwb08@...> writes:
>
> >
> > Hi All,
> >
> > I would like to calculate a dispersion parameter for a glmer with a
> > Poisson family (in lme4). I found a function posted on this mailing
> > list that had been suggested to use for calculating a dispersion
> > parameter for a glmer with a binomial family. (Found on
> > https://stat.ethz.ch/pipermail/r-sig-mixed-models/2011q1/015383.html )
> >
>
>  [snip]
>
>   Please see slightly more robust code at
>
> http://glmm.wikidot.com/faq#overdispersion_est
>
> It should be applicable to GLMMs generally, although please note all the
> boldface warnings about this being a crude approximation of the
> overdispersion parameter.
>

As you know, my opinion is that you can approximate it however you want
because it doesn't exist :-)

	[[alternative HTML version deleted]]

