Multi-speaker Utterances and Co-ordinationin Task-oriented Dialogue

Kristina Poncin and Hannes Rieser
Abstract
We investigate utterances in task-oriented dialogue which are produced by serveral agents. Starting with an example where a VP in a directive is initiated by one agent and completed by the addressee, we set out to explain under which conditions co-ordinations of this type can be successful. The explanatory devices developed are 'action schema' and 'sufficiently informative proposition'. It is argued that propositions embedded in directived must be sufficiently informative for an agent to permit a task-relevant action of his. We suggest that agents' co-ordination on sufficiently informative propositions be taken as a measure for co-ordination in dialogue. Using this idea we show how co-ordination in a full task-oriented dialogue develops. Finally, we demonstrate that agents' "point-wise" co-ordination can be explained using Asher-Morreau defeasible inference, a version of Lascarides-Asher defeasible Practical Syllogism as well as additional principles like a Co-operativity Principle and a principle saying 'Make assumed conformity of interests and intentions publicy known!'. If our arguments can be accepted this would first of all entail that theories of dialogue were to be based on co-ordination and secondly, it would also have repercussions on the notions of proposition, mutuality and common ground.
Anke Weinberger, 2001-05-02, 2002-01-10