Dear Dr. Bates,
Thank you very much for your response. I had consulted
the algorithm described in Pinheiro and Bates.
However, what I don't understand (among other things)
is why my two parameters appear to be estimated at
different grouping levels (based on the DF values).
Affect this different values of DF at the estimates
parameters? The estimates fixed effects were get at
the same level of grouping?
I apreciate any response.
Lic. Gabriela Escati Peñaloza
Biología y Manejo de Recursos Acuáticos
Centro Nacional Patagónico(CENPAT).
Bvd. Brown s/nº.