Cooperative requests and replies in a collaborative dialogue model

Abstract

In this paper, we present a computational model of dialogue, and an underlying theory of action, which supports the representation of, reasoning about and execution of communicative and non-communicative actions. This model rests on a theory of collaborative discourse, and allows for cooperative human–machine communication in written dialogues. We show how cooperative behaviour, illustrated by the analysis of a dialogue corpus and formalized by an underlying theory of cooperation, is interpreted and produced in our model. We describe and illustrate in detail the main algorithms used to model the reasoning processes necessary for interpretation, planning, generation, as well as for determining which actions to perform and when. Finally, we present our implemented system.Our data are drawn from a corpus of human–human dialogues, selected and transcribed from a day-long recording of phone calls at a phone desk in an industrial setting (Castaing, 1993). We present an analysis of this corpus, focusing on dialogues which require, in order to succeed, helpful behaviour on the part of both the caller and the operator.The theoretical framework of our model rests on the theory of collaborative discourse developed by Grosz and Sidner (1986, 1990), Grosz and Kraus (1993, 1996), and further extended by Lochbaum (1994, 1995). An important objective guiding the design of our dialogue model was to allow the agent being modelled to interpret and manifest a type of cooperative behaviour which follows Grosz and Kraus's formalization of the commitment of each collaborative agent towards the actions of the other collaborative agents. The model we propose extends Lochbaum's approach to discourse processing in extending her interpretation algorithm to allow for the treatment of a wider range of dialogues, and in providing an algorithm of task advancement which guides the generation process and allows for the interleaving of execution and planning, thereby facilitating cooperation among agents. The cooperative behaviour of the agent being modelled rests on the use of communicative actions allowing agents to share additional knowledge and assist each other in performing their actions.