On Tue, 19 Jun 2007, Ben Bolker wrote: > Yuanchang xie <xieyc <at> hotmail.com> writes: > >> >> Dear Listers, >> >> I want to compare two negative binomial models fitted using glm.nb and >> gam(mgcv) based on the same data. What would be the most appropriate >> criteria to compare these two models? Can someone point me to some >> references? Thank you very much. >> >> Yuanchang Xie > > Since they can't possibly be nested I would suggest AIC.
Surely they could be: a smooth fit in gam includes the possibility of a linear fit. What is of more concern to me is that gam() is by default itself doing model selection, so AIC is not well-defined. According to ?gam.selection, the comparisons are best done by comparing scores within mgcv. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.