Dear friends, I am apologise to ask again about PQL, because I did not receive any answer from the first question. Is it possible to fit a crossed random effects model using glmmPQL and, because I tyred to use this codes random=list(group=pdBlocked(list(pdIdent(~randf-1),pdIdent(~randm-1)))), family=binomial, data=sala.data)> for the random effects part , but dos not give me the same result as in the literatures, in particular, for the random effects, and when I change the number of groups it gives me different result. So, If any one has an idea, pleas help me Note that the data what I am trying to fit are the salamander mating data E-mail:aleid2001 at yahoo.com