Message-ID: <93CBC95C-6C8A-4234-B6BA-347BA18204BF@sms.ed.ac.uk>
Date: 2014-11-07T11:18:04Z
From: FERNANDEZ Ana maria
Subject: MCMCglmm Heterogenous Residual Variance in a Categorial Model
Dear List,
I was wondering what the recommendation is for structuring residual variances in the context of a categorial model when you have a sex interaction in the random term of the model (where animal is the pedigree structure).
MCMCglmm course notes have a brief recommendation about sex interaction and allowing the sexes to have different residual variances: "3.4 Heterogenous Residual Variance To be started... In short - if you?ve fitted a sex by dam interaction I would always allow the sexes to have different residual variances. Use rcov=?idh(sex):units.?
But the conflict that I am coming across is another recommendation about how the residual term should be- or needs to be- fixed in a categorical model.
I have a case-control binary response variable and I want to look at the sex effect interaction.
Let me know if you need more detail.
Thanks!
Maria
Ana Maria Fern?ndez Pujals
A.Fernandez-2 at sms.ed.ac.uk<mailto:A.Fernandez-2 at sms.ed.ac.uk>
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