tailieunhanh - Báo cáo khoa học: "Modifying Beliefs in a Plan-Based Dialogue Model"

Previous models of discourse have inadequately accounted for how beliefs change during a conversation. This paper outlines a model of dialogue which maintains and updates a user's multi-level belief model as the discourse proceeds. This belief model is used in a plan-recognition framework to identify communicative goals such as expressing surprise. | Modifying Beliefs in a Plan-Based Dialogue Model Lynn Lambert Department of Computer and Information Sciences University of Delaware Newark Delaware 197161 1 Introduction Previous models of discourse have inadequately accounted for how beliefs change during a conversation. This paper outlines a model of dialogue which maintains and updates a user s multi-level belief model as the discourse proceeds. This belief model is used in a plan-recognition framework to identify communicative goals such as expressing surprise. 2 Plans Beliefs and Processing My plan-based model of dialogue incrementally builds a structure of the discourse a Dialogue Model or DM using a multi-level belief model updated after each utterance. The belief model contains the beliefs ascribed to the user during the course of the conversation and how strongly each belief is held. Researchers 1 3 5 have noted that discourse understanding can be enhanced by recognizing a user s goals and that this recognition process requires reasoning about the agent s beliefs 7 . For example in order to recognize from utterance IS2 in the following dialogue that the speaker has the communicative goal of expressing surprise at the proposition that Dr. Smith is teaching CIS360 and not just asking if Dr. Smith is teaching CIS420 it is necessary for the system to be able to plausibly ascribe to IS the beliefs that 1 Dr. Smith is teaching CIS420 2 that this somehow implies that Dr. Smith is not teaching CIS360 and 3 that IP believes that Dr. Smith is teaching GIS360. ISi Who is teaching CIS 360 IPi Dr. Smith. IS2 Dr. Smith is teaching CIS 420 isn t she IP2 Yes she is. Dr. Smith is teaching two courses. IS3 What time is CIS 360 My model ascribes these beliefs to IS as the discourse proceeds and uses the ascribed beliefs for recognizing utterances that involve negotiation dialogues. Without the ability to modify a belief model as a dialogue progresses it would not be possible to plausibly ascribe 1 or 3 so it is unclear how