Elena A. Erosheva
This paper employs a geometric approach for describing population heterogeneity representations of different discrete data models. The case of a contingency table is considered in details. The paper provides geometric representations for log-linear, latent class, Grade of Membership and Rasch models in the marginal space (based on marginal probabilities) and in the full parameter space (based on cell probabilities). The approach generalizes case to higher dimensions, i.e., to 2J tables with . A discussion of similarities and differences among the models is included.
Keywords: Geometric approach, contingency table, Marginal probabilities, Cell probabilities, Local independence.