Although multidimensional item response theory (IRT) (e.g., McDonald, 1962, 1997; Reckase, 1985, 1997; Samejima, 1974) has been available for some time, it has been applied much less frequently in adaptive testing than unidimensional IRT. The main reason for this was a lack of computational power. However, recently this condition has changed dramatically. Even for the more time-intensive Bayesian treatments of multidimensional models, regular PCs now have plenty of computational power to deal with them in a large variety of applications.