In this case, R-side would index each dog within an owner, as if the owner were measured on successive time points or at geographically defined points. G-side would add columns to the Z matrix so that each owner is viewed as a cluster of dogs, and a variance component (or components) is estimated. For what you are doing, I don't see any need for R side approach. Now a key here is the distribution associated with the response variable. Be sure that the link associated is appropriate--cumulative logit for ordinal categories and generalized logit for nominal categories. Steve Denham
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