How disagreement expressions are used in cooperative tasks

Analysis was made of disagreement expressions in dialogues recorded in a cooperative task experiment. A disagreement expression is de ned as the latter utterance of consecutive utterances, which shows disagreement with the former. Subjects used two types of disagreement expressions: to the partner's utterance, and to their own. These were classi ed into three subtypes according to part of speech: conjunction, interjection, and content word. The role of disagreement expressions in cooperative tasks was examined. It was found that subjects used disagreement expressions suitable to the occasion to maintain good relation with their partners. It was concluded that using expressions that disagree with one's own previous utterance is an e ective strategy for expressing an opinion for which one lacks adequate evidence and for eliciting utterances from one's partner.