H.J. Lebbink

Dialogue Games for Inconsistent and Biased Information

In this article, a dialogue game is presented in which coherent conversational sequences with inconsistent and biased information are described at the speech act level. Inconsistent and biased information is represented with bilattice structures, and based on these bilattice structures, a multi-valued logic is defined that makes it possible to describe a dialogue game in which agents can communicate about their cognitive states with inconsistent and biased information. A dialogue game is formalized by, first, defining the agents cognitive state as a set of multi-valued theories, second, by defining the dialogue rules that prescribe permissible communicative acts based on the agents cognitive state, and last, by defining update rules that change the agents cognitive state as a result of communicative acts. We show that an example dialogue with inconsistent and biased information can be derived from our dialogue game.

A Dialogue Game to Offer an Agreement to Disagree

This paper proposes a dialogue game in which coherent conversational sequences at the speech act level are described of agents that become aware they have an irresolvable disagreement and settle the dispute by agreeing to disagree. A disagreement is irresolvable from an agentýs perspective if both agents are aware that they both ran out of options to resolve the situation. A dialogue game is formulated in which agents can offer information that may result in non-reconcilable, mutually inconsistent belief states. An agentýs cognitive state consists of mental constructs, and given on these constructs, epistemic operators are defined which are used to define dialogue rules and a cognitive rule that allow an agent to agree to disagree.

Can I Please Drop It? Dialogues About Belief Contraction

This paper presents a dialogue game in which agents in a multiagent system try to contract beliefs in agreement with other agents. The dialogue game defines the semantics of the communicative act of asking support to contract beliefs. In addition, a decision game is presented that defines when agents are allowed to contract propositions from their private belief states. These games if combined allow agents to contract beliefs in a distributed fashion.