Interpreting the output of summary() of a glmer-object
Hans Ekbrand <hans at ...> writes:
On Tue, Sep 25, 2012 at 02:04:19AM +0000, Ben Bolker wrote:
Hans Ekbrand <hans at ...> writes:
[snip]
load(url("http://sociologi.cjb.net/temp/a.strange.df.RData"))
my.fit.1 <- glmer(MV744A ~ (1|MV024),
data = a.strange.df, family = "binomial")
summary(my.fit.1)
[snip]
Random effects: Groups Name Variance Std.Dev. MV024 (Intercept) 0.40558 0.63685 Number of obs: 73601, groups: MV024, 29
[snip]
So, if I understand you - which I think I do - then 0.63685 is simply the standard deviation of ranef(my.fit.1)? When I try to compute that manually I get a numerically close figure, but not quite the same: sd(unlist(ranef(my.fit.1))) [1] 0.6423346 I am on the right track?
I think this has been discussed previously on the list (although I can't point you to a precise spot), but: http://permalink.gmane.org/gmane.comp.lang.r.lme4.devel/8580 says "Generally you will find that the variance of the values returned by ranef is less than the estimated variance because of shrinkage." Sorry I can't go into more detail right now.