A multi-modal dialogue system for information navigation and retrieval across spoken document archives with topic hierarchies

Unlike the written documents, the spoken documents are difficult to be shown on the screen and browsed by the user during retrieval. In this paper, we propose to use multi-modal dialogues to help the user to "navigate" across the spoken document archives and retrieve the desired documents based on a topic hierarchy constructed by the key terms extracted from the retrieved spoken documents. An initial prototype system for such functions has been developed, in which the broadcast news in Mandarin Chinese was taken as the example spoken documents, and the named entities (NEs) are taken as the key terms to construct the topic hierarchy.