[R-sig-ME] handling overdispersion in poisson random effects models

[David Duffy]

On Fri, 1 Jul 2011, O'Reilly, Kathleen M wrote:

> However I get the following error when running M2
> "Error in function (fr, FL, glmFit, start, nAGQ, verbose)  :
>  Number of levels of a grouping factor for the random effects
> must be less than the number of observations"
>
> Other people seem to run the equivalent of M2 without error.

Yes, it's just your version of lme4 must be a bit old.  This test was too 
cautious (it breaks the pedigreemm package, among other things).

Cheers, David Duffy