Abstract

For several years the research group at our Dialogue Systems Lab has been involved in the development of the information state update approach to the building of dialogue systems and in particular Issue based dialogue management developed in Staffan Larsson's PhD thesis and based on Jonathan Ginzburg's gameboard approach to dialogue, focussing on the notion of questions (or issues) under discussion. Larsson's computational approach to information state updates involves a large collection of update rules which fire when certain conditions in the information state are met in a regime determined by a general control algorithm. An utterance by a dialogue participant will in general unleash a whole chain of such updates and part of the power of the approach lies in the fact that we can define very general update rules which have small effects on the information state and which are not necessarily linked to any particular form of utterance. It gives us a much finer grain on update rules than thinking in terms of single monolithic updates associated with speaker utterances.