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some questions about "lmer" in GLMM
2 messages · Maddie Wang, David Duffy
On Tue, 8 May 2012, Maddie Wang wrote:
Hi.
I have a question about lmer for GLMM that I cannot find an answer on-line for quite a bit time. Suppose the response y is from a binomial distribution. The GLMM can be written as logit(pi)=x*\beta+z1b1+z2b2+z3b3, where pi is the expectation of binomial proportion, \beta is the fixed coefficients, b1,b2 and b3 are three random effects, where b1 is from a multivariate normal MN(0, \tau1 * I_(3X3)), b2 is from a multivariate normal MN(0, \tau2 * I_(3X3)), and b3 is from a multivariate normal MN(0, \tau3 * I_(4X4)).
I'm having trouble understanding your setup. Why is b3 4X4 - are these crossed indicator variables with 3,3,4 levels? And if so, what design and how much data? Are the taus prespecified somehow? Cheers, David Duffy.