Re: [R] glmm: random term, overdispersion and comparisons

2015-10-02 Thread Thierry Onkelinx
Dear Ellen, You're using the Poisson distribution. There is no error (noise) term in a glmm with Poisson distribution. 1) The random part seems to be quite complicated given the sample size. (1|site) is probably sufficient. Note that your design is not nested but crossed. 2) Overdispersion is lik

[R] glmm: random term, overdispersion and comparisons

2015-10-01 Thread Ellen Andresen
Hello, I studied the effect of a hurricane in Cozumel on understory birds. I have bird abundances (i.e. counts) registered always on the SAME six sites (i.e. blocks). I have data for: before the hurricane, first year after the hurricane, second year after the hurricane. I each of these time periods