Section: New Results
Intermediate dependency generative models
Participants : Christophe Biernacki, Matthieu Marbac-Lourdelle, Vincent Vandewalle.
Defining generative models for dealing with possibly correlated categorical variables is at the core of the modal activity. We start by noticing that it is straightforward to build a full independent distribution and also a full dependent one in the categorical situation. However, both are usually too crude for modelizing most of real situations.
Our idea is to combine both extreme distributions and in order to obtain a new distribution called (i) which is an intermediate dependent situation between full independence and full dependence and (ii) which is not degenerate. As a consequence, is a meaningful distribution because its particular “positioning” between and directly models and reveals strength of dependency between variables.
In addition, since both and are easily available for most variables types, we expect to be able to design a distribution for most variables types, and not also the categorical ones.
A PhD thesis started on October'11 on this topic in continuation of the Master's thesis of Matthieu Marbac-Lourdelle [37] .