731
Elena A. Erosheva
This paper employs a geometric approach for describing population
heterogeneity representations of different discrete data models. The
case of a 2 x 2 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 2 x 2 case to
higher dimensions, i.e., to 2 J tables with . A
discussion of similarities and differences among the models is
included.
Keywords: Geometric approach, 2 x 2 contingency table, Marginal probabilities, Cell probabilities, Local independence.