An event driven model for dialogue systems

This paper reports our progress in building a mixed initiative, goal-oriented dialogue system for human machine interactions. The dialogue model embraces the spirits of the so-called planbased approach in that the dialogue flow is not statically authored but dynamically generated by the system as a natural outcome of the semantic evaluation process. With multimodal applications in mind, the dialogue system is designed in an event driven architecture that is commonly seen in the core of a graphical user interface (GUI) environment. In the same manner that GUI events are handled by graphical objects, the proposed dialogue model assigns dialogue events to semantic objects that encapsulate the knowledge for handling events under various discourse contexts. Currently, we have found that four types of events, namely, dialogue object instantiation, semantic evaluation, dialogue repair, and discourse binding, are sufficient for a wide range of applications.