mixed models without residual term
On Fri, Feb 22, 2008 at 2:57 AM, De Maeyer Sven <sven.demaeyer at ua.ac.be> wrote:
Dear List members,
I'm a recently new user of R and lme4. In some of my research designs I used to estimate mixed models without a residual term. Only random effects were added, but no residual. I did this in MlwiN. Now I'm trying to do the same analyses with lmer, but I can't seem to fix the residual to zero. Is this currently possible in lme4?
I don't think so. The models that can be fit with the lme4 package are all based on the assumption that the response vector is an n dimensional random variable. I'm not sure how to define maximum likelihood estimates for parameters based on observed data without a probability model for the distribution of the response vector.