Hi,
I have to analyse the number of provisioning trips to nestlings according to a number of biological and environmental factors. I was thinking of building a mixed-effects model with species and nestid as random effects, using a Poisson distribution, but the data are overdispersed (variance/mean = 5). I then thought of using a mixed-effects model with negative binomial distribution, but I have 2 problems: 1- The only package building mixed models with neg. bin. distribution I found is the package glmmADMB but I have a hard time understanding the output. Anyone knows of a R package with an output that gives p values? 2- Two people I asked advice to told me that I should use either a mixed-effect model with a Poisson distribution (the random effects will take care of the overdispersion) OR a glm using neg. bin. distribution but not both at the same time, which would be unnecessary. Any advice is welcome! Thank you Marie-Helene Hachey M.Sc. student Universite Laval, Quebec ______________________________________________ R-help@r-project.org 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.