Latent class analysis with ordered latent classe

In this paper a latent class model is described in which the latent classes are ordered imposing inequality constraints on item response and cumulative response probabilities from subsequent latent classes. These inequality constraints are derived from the basic assumption that, when the latent classes may be ordered from low to high along the latent continuum, the probability of a ‘positive’ response should increase monotonically as one moves along this continuum. An algorithm to obtain the maximum likelihood estimates of the model parameters is proposed and is applied to a real data set.