A Task-Independent Control Method for Spoken Dialogs

摘要

In this paper the authors propose a task-independent control method for spoken dialogs. This is an expansion of the frame-driven dialog control method used in text-based dialog systems, which employs knowledge specific for a task using a database and frames. The frame consists of a set of related topics that can be treated in specific tasks, the priority ranking, and the behavior of the system when each topic is completed. When there is a hierarchical relationship among topics, this is described as a hierarchical relationship among frames. The dialog history is represented by the topic frame using a tree structure that can provide dynamic links (this is called a dynamic topic tree). System-initiative and user-initiative dialog can be accomplished by searching the dynamic topic tree using two types of approaches. The authors created a spoken dialog system for four typical tasks and performed spoken dialog experiments in order to evaluate the system. The results showed that all subjects were able to complete the tasks. This demonstrates that the authors' method is valid as a way to create a practical task-independent spoken dialog system.