GENERATING QUERIES AND REPLIES DURING INFORMATION-SEEKING INTERACTIONS

Analysis of naturally occurring information-seeking dialogues indicate s that they usually consist of a number of distinct discourse segments , such as a greeting segment, a request issued by a user, an optional clarification segment, a transfer of information segment and a final c losing segment. The clarification interaction is often initiated by th e information provider and it may be due to one of the following reaso ns: (1) there is confusion regarding the user's intentions, (2) there is insufficient information to formulate a plan to satisfy a recognize d intention, or (3) there is difficulty in formulating a plan that sat isfies a recognized intention. Once the information provider determine s the user's intention and formulates a plan to achieve this intention , the information transfer phase is initiated to inform the user about the proposed plan. In this paper, we present a mechanism for generati ng queries during the clarification stage and answers during the infor mation transfer stage. Given a hierarchical representation of the alte rnatives possibly intended by a user and the probabilities of these al ternatives, our mechanism determines the hierarchy level at which a qu ery must be directed and the query to be posed in order to determine t he alternative intended by the user. Once the user's intentions are as certained, the mechanism determines whether additional information is required and the manner in which queries may be posed to acquire this information. When a user's intentions cannot be satisfied by means of a single plan, our mechanism enters into a negotiation process to alte r the user's specifications until a valid plan is formulated. In the f inal stages of the interaction, the mechanism determines the informati on to be transferred and generates an answer to effect the transfer. T he mechanisms for negotiation and for the generation of queries and an swers described in this paper have been implemented in a system called RADAR, a computerized information providing system that functions as a travel agent. (C) 1997 Academic Press Limited.