[R-sig-ME] mixed model testing

Irene Mantzouni ima at difres.dk
Wed Nov 7 15:55:22 CET 2007

Is there a formal way to prove the need of a mixed model, apart from e.g. comparing the intervals estimated by lmList fit? 
For example, should I compare (with AIC ML?) a model with seperately (unpooled) estimated fixed slopes (i.e.using an index for each group) with a model that treats this parameter as a random effect (both models treat the remaining parameters as random)?
Thank you!

More information about the R-sig-mixed-models mailing list