The objective of this project is to develop a more robust process model of plan recognition without the restrictive assumptions of previous systems. In order to effectively engage in a cooperative dialogue, a natural language system must be able to infer a user's plan recognition have made several restrictive assumptions that prevent them from handling naturally occurring dialogues. These assumptions include: 1) a user cannot intend that the system recognize his/her goal unless it is the only goal that can account for the current dialogue in the given situation, and 2) the model inferred by the system is always in total agreement with the task related plan under construction by the user. This project will investigate a more robust model of plan recognition without these unrealistic assumptions and which therefore will be able to handle dialogues that are less than ideal. Our approach will be to study hjow evidential reasoning techniques can be used to facilitate rational and natural recognition of user intention in the presence of multiple alternatives and how techniques for handling ill formed input can be applied to the problem of recognizing and recovering from errors in the system's model of the user's plan.
