I agree with David. A dispersion parameter of 25 suggests that you have
mainly 0's in your data set and your model is not adequate. Perhabs you
should dichotomize your data in 0 and 1's and use a logistic mixed model but
be aware of small numbers of events.
That amount of overdispersion would
Hi all,
I was wondering if somebody could give me advice regarding the
dispersion parameter in GLMM's. I'm a beginner in R and basically in
GLMM's. I've ran a GLMM with a poisson family and got really nice
results that conform with theory, as well with results that I've
obtained previously
That amount of overdispersion would make the use of a poisson model
very questionable, and will very likely result in estimated standard
errors that are too low, hence the change in statistical significance
when you switch to quasipoisson.
On 06/03/07, Cristina Gomes [EMAIL PROTECTED] wrote:
Hi
