[R] lme nested

[Leonardo D Bacigalupe]

Hello all,

I have a question regarding how to specify a nested model with mixed 
factors in lme.

If I have a nested design with 2 factors (A and B), with B nested 
within A and with y as the dep var, then,
if both A and B are random the model should read y~1,random=~1|A/B.

Now if factor A is fixed (and this is where i get confused) how should 
be the model:

(1) y~A,random=~1|A/B (in this option A is also random and should be 
only fixed e.g. treatment)
(2) y~A,random=~A|B  (does the A|B define the nested structure?)

thanks
leonardo





Leonardo D. Bacigalupe

Department of Animal and Plant Sciences
University of Sheffield
Sheffield S10 2TN
United Kingdom

L.Bacigalupe at sheffield.ac.uk