Topic Forest: a plan-based dialog management structure

There are many task-oriented dialog systems, but few of them can cope with the issues such as the multiple-topic issue, the topic changing issue, the information sharing among different topics, and the difference in importance for different information items. To provide efficient solutions, a plan-based dialog management structure named Topic Forest is proposed, which makes the mixed-initiative dialog control easier. The Topic Forest based reasoning engine with a certain strategy for both remembering and forgetting is also described. The reasoning strategy is designed to be domain-independent; therefore it makes the dialog management model easy to be ported to any other different domains.