Nested random effect within fixed effect factor?

Thanks. Yes this partitions the error variance, but not the random effect
variance. That part is working fine (and in fact matches what I get from
running both subsets). But still curious about the random effects being
different.

I'm not sure you're right in characterizing it that way.  My simple-minded 
understanding (I would be grateful for correction) is that you can get 
equivalent models by either modeling the off-diagonal covariances for Z or 
for e, since here you don't have an informative design (some clusters or 
individuals receiving both treatments).


| David Duffy (MBBS PhD)                                         ,-_|\
| email: davidD at qimr.edu.au  ph: INT+61+7+3362-0217 fax: -0101  /     *
| Epidemiology Unit, Queensland Institute of Medical Research   \_,-._/
| 300 Herston Rd, Brisbane, Queensland 4029, Australia  GPG 4D0B994A v