Yes, use type=twolevel and estimator=wlsmv. It might be helpful to look at example 9.9 in the users guide (except you won't have a between level factor). You can also take a look at this paper and the simulation study in section 5. http://statmodel.com/download/p2t1.pdf
I think you are running into the problem of too many dimensions of integration. With ML, you should fix the residual variances to zero, u1-u10@0; If you don't, each one requires one dimension of integration.
Uwe Braut posted on Thursday, March 15, 2012 - 8:49 pm
Thank you again for the advice but, unfortunately, these commands do not seem to work. They do not give me a single random effect for the items difficulties.
Do you want only a single random effect for the item difficulties, or do you want as many random effects as there are items? In principle each item could have a random difficulty.
Is there a specific model in the literature that you want to capture?
Uwe Braut posted on Thursday, March 15, 2012 - 11:06 pm
The notion of item-specific random effects is interesting but I want a single random effect for the item difficulties. This model is described, for example, by Van den Noortgate, W., De Boeck, P., & Meulders, M. (2003). Cross-classification multilevel logistic models in psychometrics. Journal of Educational and Behavioral Statistics, 28, 369–386.