A reparameterization of a latent class model is presented to classify and scale nomial and ordered categorical choice data simultaneously. The model extension represents a nonhomogeneous population as a mixture of homogeneous subpopulations. Simulated data and data from a magazine preference survey of 347 college students illustrate the model.…

Two sets of real sorting data from 50 college students are used to compare results of multidimensional scaling of raw co-occurrence frequencies or dissimilarity measures (D) and profile distances (delta) to determine which yields a better representation of the underlying structure of 2 sets of stimuli. Slight differences are discussed. (SLD)

Equatings were performed on both simulated and real data sets using common-examinee design and two abilities for each examinee. Results indicate that effective equating, as measured by comparability of true scores, is possible with the techniques used in this study. However, the stability of the ability estimates proved unsatisfactory. (TJH)