# Model validation of quasi-Poisson

I have been running a set of quasi-Poisson generalized linear models. As there is no AIC computed with quasi-distributions I was wondering how I could compare my models. It seems that I can use QAIC but I am really confused by all the reading I have done. Is there a simple function that I can use for that?

• The R package AICcmodavg has a QAIC function & references Burnham & Anderson (2002), Model Selection & Multi-Model Inference. – Scortchi Aug 12 '13 at 16:47

## 1 Answer

Hy, Elena, jast look on deviance (& rdf), the smaller Dev. is the better! Gama pdf has additional parameter and may be useful. In my experience (hardest case: exess of zeros & overdispersion!) the PGAM package (in R) was a better choice ;-) NegBin & QPoisson + hurle models ... all are failed :-(

• Where's the penalty for bigger models if you just look at deviance? – Scortchi Aug 12 '13 at 15:18