Statistics Seminar Speaker: Helene Massam, 12/2/2015

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Wednesday Dec 02 2015

Statistics Seminar Speaker: Helene Massam, 12/2/2015

4:15pm @ G01 Biotechnology

The Statistics Seminar Speaker for December 2 is Helene Massam, professor in the department of Mathematics and Statistics at York University. For more information, including Massam's publications list, visit her webpage.

Title: A New Prior for Discrete DAG Models with a Restricted Set of Directions

Abstract: In the present literature, prior distributions for discrete directed acyclic graph (DAG) models are either derived from the Dirichlet distribution on the complete model or consists of a set of different Dirichlet priors for each vertex of the DAG and each configuration of its parents.

In this talk, we develop a new family of conjugate prior distributions for the cell probability parameters of discrete graphical models Markov with respect to a set $\cP$ of moral directed acyclic graphs with skeleton a given decomposable graph $G$. This family, which we call the $\cP$-Dirichlet, is a generalization of the hyper Dirichlet: it keeps the directed strong hyper Markov property of the hyper Dirichlet for every DAG in $\cP$ but increases the flexibility in the choice of its parameters, i.e. the hyper parameters.

We also give a characterization of this $\cP$-Dirichlet which yields, as corollaries, a characterization of the hyper Dirichlet and a characterization of the Dirichlet. 

Refreshments will be served after the seminar in 1181 Comstock Hall. 

PDF iconHelene_Massam[1].pdf