A model of plan recognition in discourse must be based on intended recognition, distinguish each agent's beliefs and intentions from the other's, and avoid assumptions about the correctness or completeness of the agents' beliefs. In this paper, we present an algorithm for plan recognition that is based on the SharedPlan model of collaboration (Grosz and Sidner, 1990; Lochbaum et al., 1990) and that satisfies these constraints. INTRODUCTION To make sense of each other's utterances, conversational participants must recognize the intentions behind those utterances. Thus, a model of intended plan recognition is an important component of a theory of discourse understanding
