A plan - based model of misunderstandings incooperative

We describe a plan-based agent architecture that models misunderstandings in cooperative NL agent communication; it exploits a notion of coherence in dialogue based on the idea that the explicit and implicit goals which can be identiied by interpreting a conversational turn can be related with the previous explicit / implicit goals of the interactants. Misunderstandings are hypothesized when the coherence of the interaction is lost (i.e. an unrelated utterance comes). The processes of analysis (and treatment) of a misunderstanding are modeled as rational behaviors caused by the acquisition of a supplementary goal, when an incoherent turn comes: the agent detecting the incoherence commits to restore the intersubjectivity in the dialogue; so, he restructures his own contextual interpretation, or he induces the partner to restructure his (according to who seems to have made the mistake). This commitment leads him to produce a repair turn, which initiates a subdialogue aimed at restoring the common interpretation ground. Since we model speech acts uniformly with respect to the other actions (the domain level actions), our model is general and covers misunderstandings occurring at the linguistic level as well as at the underlying domain activities of the interactants. 1 The phenomenon of misunderstandings 1.1 INTRODUCTION In order for a dialogue to proceed successfully, it is important that the speakers maintain a consistent view of the interaction. Nevertheless, vagueness and ambiguities can intervene in a speaker's utterance and interfere with the process of interpretation of that utterance. Many researchers have recognized the role of various ambiguity types in generating misunderstandings, from diierent perspectives In the linguistic and philosophical research, misunderstandings have been analyzed under diierent points of view: for example, Zaeeerer (1977) and Dascal support the idea that the study of misunderstandings is related with comprehension in an indirect, external way, \much in the same way as pathological behavior is often said to be able to illuminate the nature of`normal' behavior" (Dascal 1989). More recently, misunderstanding