Goal Management for a Multisession Dialogue

The goal management is a difficult task for a spoken dialogue system, especially for the multisession dialogue. Instead of engaging a single user and the dialogue system in an ordinary dialogue, a multisession dialogue eventually invokes multiple successive users related by resource conflicts. Thus, the dialogue system should take an intermediary role to communicate with these users by creating several successive sessions in order to reach a better compromised solution among them. In this paper, we present an approach to managing the goal of a multisession dialogue by using an AND-OR tree, in order to bring the performance to our spoken dialogue system. In common with the notion of dialogue agenda, a multisession dialogue is totally managed by using a tree of conflicting goals. The results of experiments performed with the dialogue system Melina show the efficiency of our approach in order to solve the resource conflicts along a series of sessions and with different related users.