THE MULTIDIMENSIONAL RANDOM-COEFFICIENTS MULTINOMIAL LOGIT MODEL

A multidimensional Rasch-type item response model, the multidimensiona l random coefficients multinomial legit model, is presented as an exte nsion to the Adams & Wilson (1996) random coefficients multinomial leg it model. The model is developed in a form that permits generalization to the multidimensional case of a wide class of Rasch models, includi ng the simple logistic model, Masters' partial credit model, Wilson's ordered partition model, and Fischer's linear logistic model. Moreover , the model includes several existing multidimensional models as speci al cases, including Whitely's multicomponent latent trait model, Ander sen's multidimensional Rasch model for repeated testing, and Embretson 's multidimensional Rasch model for learning and change. Marginal maxi mum likelihood estimators for the model are derived and the estimation is examined using a simulation study. Implications and applications o f the model are discussed and an example is given.