[R-sig-ME] new R user struggling with error and convergence issues

[Ben Bolker]

Jennifer Yourkavitch via R-sig-mixed-models <r-sig-mixed-models at ...> writes:

> 
> Follow-up: glmmPQL works like a charm. I don’t really
>  understand the difference between the algorithms
> used by glmmPQL and glmer. Should I be concerned that 
> the models ran with glmmPQL but not glmer?
> Thanks,
> Jennifer
> 

  The main case where Laplace approximation (the default glmer
algorithm) is significantly better than PQL is when there are a
small number of values per group; PQL depends more strongly than
Laplace approximation on the approximate Normality of the sampling
distributions of the conditional modes (predictions of the random
effects for particular groups).
   Do the predicted values make sense?

  Ben Bolker