Arguing About Planning Alternatives

In discourse processing, two major problems are understanding the underlying connections between succe~ive dialog utterances and deciding on the content of a coherent dialog response. Thin paper presents a computational model of these tasks for a restricted class of argumentative dialogs. In these dialogs, each response presents a belief that justifies or contradicts another belief presented or inferred earlier in the dialog. Understanding a response involves relating a stated belief to these earlier beliefs, and producing a response involves selecting a belief to justify and deciding upon the set of beliefs to provide as its justification. Our approach is knowledge baaed, using general, common-sense justification rules to recognize how a belief in being justified and to form new justifications for beliefs. This approach provides the ability to recognize and respond to never before seen belief justifications, a necessary capability for any system that participates in dialogs involving disagreements.