Comments: WAA17776 on willow (hop 0), Mon, 15 Dec 1997 22:29:16 -0500 (EST)
I am running some analysis with binary data in trees, using 0/1 data
directly (not proportion or percent) and probit as link function
(model: x !bin !probit !wt=0 ~ mu !r fam)
Problem 1: I am confuse with the interpretation of variance components.
Source Model terms Gamma Component Compnt/StndErr
fam 80 80 0.165261 0.165261 4.39
Variance 1920 1919 1.00000 1.00000 0.00
I understand the variance components are expressed on underlying scale
(threshold model). In the example above the family variance component is
0.165261. But what about the error variance component? Is it just 1-
0.165261=0.834739? If this is true, then, ASREML just sets the phenotypic
variance to 1 without estimation of the other portion of the variance. Is
Problem 2: When dealing with binomial data, does Asreml use the methods
described in Gilmour et al 1985 (The analysis of binomial data by a
generalized linear mixed model)? Or other methods are used?
Thank you very much all of you.
Have a happy new year.