[R-sig-ME] Model fit after false convergence

[David Duffy]

On Tue, 27 Oct 2009, Luciano La Sala wrote:

> Dear R-crew, 
> 
> I am using lmer to fit a model for epidemiological data. I start from a 
> saturated model containing all the main effects of interest (all with p < 
> 0.25 in a bivariate screening) plus one random intercept (please see 
> below). From there, I need to refine my model based on AIC criterion.
> 
> As you can see below, I'm getting a convergence error after fitting the 
> saturated model, which I don't know how to deal with.

Does the equivalent fixed effects model (ignoring nest) converge?  Maybe
there is separation.

Cheers, David Duffy.