Modelling and analysis of multivariate ordinal categorical data in longitudinal set up

Abstract

In recent years, there has been a tremendous continuing attention to- wards the modelling and analysis of longitudinal data, although not much attention is paid to the ordinal categorical data. The problem becomes more complicated if the observation at every longitudinal time point is multivariate, and every component of the response vector is ordinal categorical. We develop urn model-type joint probability models with diff erent correlation structures when the data are of a longitudinal bivariate ordinal nature, and discuss the methods of their estimation. Some examples which motivate us to model and analyse such kind of data are also discussed.