In this paper, it is shown how the approach of Gibbons and Hedeker (1992) can be placed into a graphical framework. The advantage of the graphical model framework is that efficient estimation schemes can be derived in a fully automatic way by applying algorithms to the graphical representation of a statistical model. This renders the approach fairly generally applicable, and tedious derivations by hand are no longer involved. The generality of the approach is demonstrated by applying it to a multidimensional IRT model with a second order dimension. It turns out that full information maximum likelihood estimation for such a model also requires the evaluation of two-dimensional integrals only.