Dear all,
I seek input on the following issue: I have two competing
models that I was hoping to compare based on the likelihood. I used REML method
and upon performing anova(fiitedobject1,fittedobject2), the following *warning* message was obtained.
…….Likelihood comparisons are not meaningful
for objects fit using restricted maximum likelihood and with different fixed
effects…..
It is true that my models differ only with respect to a
single fixed effect parameter.
I would like to know some references that address the
underlying reason. I did perform internet search and looked at Mixed-effects
modeling in S and S-Plus by Pinheiro and Bates but haven’t understood the
issue completely. There is some mention of it in the book while explaining the estimation
methods. Are there any other references?
Thanks,
Pravin
Pravin Jadhav