MULTIDIMENSIONAL RASCH MODELS FOR PARTIAL-CREDIT SCORING

Rasch models for partial-credit scoring are discussed and a multidimen sional version of the model is formulated. A model may be specified in which consecutive item responses depend on an underlying latent trait . In the multidimensional partial-credit model, different responses ma y be explained by different latent traits. Data from van Kuyk's (1988) size concept test and the Raven Progressive Matrices test were analyz ed. Maximum likelihood estimation and goodness-of-fit testing are disc ussed and applied to these datasets. Goodness-of-fit statistics show t hat for both tests, multidimensional partial-credit models were more a ppropriate than the unidimensional partial-credit model.