Dear R-List,
I have a data set (available on request) of observations from
a 2x2 conditions psychological experiment, with count of
correct/wrong decisions, and vp as the subject id.
$ vp : Factor w/ 10 levels
"1","10","2","3",..: 1 1 1 1 1 1 1 1 2 2
...
$ bed : Factor w/ 2 levels "Hz15","Hz1": 1 1 1 1 2 2 2
2 1 1 ...
$ task : Factor w/ 2 levels "n","p": 1 1 2 2 1 1 2 2 1 1
...
$ decision: Factor w/ 2 levels "corr","wrong": 1 2 1 2 1 2
1 2 1 2 ...
$ count : int 20 14 25 26 5 29 27 7 7 10 ...
Analyzed by glmmPQL, the result is meaningful and "as expected"
--------------------------------------------
gep<-glmmPQL(decision~bed+task+bed*task,data=mag3,random=~1|vp,
weights=count, family=binomial )
Fixed effects: decision ~ bed + task + bed * task
Value Std.Error DF t-value p-value
(Intercept) -0.666 0.504 65 -1.32 0.1910
bedHz1 1.187 0.746 65 1.59 0.1163
taskp 1.359 0.663 65 2.05 0.0443
bedHz1:taskp -2.328 0.986 65 -2.36 0.0213
I first had tried with geese (from geepack), but
the results were totally off.
Is this a convergence or my error in specifying
the model?
------------------------
geese(decision~bed+task+bed*task,data=mag3,id=vp,
weights=count, family=binomial)
Coefficients:
estimate san.se wald p
(Intercept) 3.36e+16 6.48e+14 2696 0
bedHz1 3.14e+16 9.54e+14 1081 0
taskp 3.54e+16 5.50e+14 4155 0
bedHz1:taskp -6.18e+16 1.14e+15 2934 0
Scale Model:
Scale Link: identity
Estimated Scale Parameters:
estimate san.se wald p
(Intercept) 2.31e+15 1.36e+38 2.91e-46 1
Correlation Model:
Correlation Structure: independence
Returned Error Value: 1
Number of clusters: 10 Maximum cluster size: 8
------------
Dieter Menne