[R] Multilevel analysis with package lme

[Felix Eschenburg]

Dear list,
i am a student of psychology and have to do a multilevelanalysis on some data. 

About that i have one general and one specific question.

This is what i have copied from the help-file on lme:
  data(bdf)
     fm <- lme(langPOST ~ IQ.ver.cen + avg.IQ.ver.cen, data = bdf,
               random = ~ IQ.ver.cen | schoolNR)
     summary(fm)

after summary(fm) i get the following error:
Error in verbose || attr(x, "verbose") : invalid `y' type in `x || y'

I assume that i have not installed the package nlme correcty, but reinstalling 
did not fix that error. So, what can i do about that ?


Then i have another question about my data.
I have one response variable and about 20 explanatory variables. These 
variables are nested in a grouping variable of about 100 groups, which is 
nested in another grouping variable of 2 groups .
I have tried this 
lme.model <- lme(respVar~expVar1, data=myData, random = respVar1+...
+respVar20| groupingVariable_level2,na.action=na.omit)

As i understood Snijders and Bosker, with that i have a fixed effect of 
expVar1 on respVar and a random effect of all the others explanatory 
variables. They are also nested in grouping Variable level 2.
Now my question is, if this is the correct term and how do i include the 
groupingVariable 3 into my model ?
As you can see, i just begun to learn about multilevelanalysis, so if you have 
a link, where it is explained, how to do that with R, I would be very 
thankful.
Yours sincerly
Felix Eschenburg