Effect of modality on collaboration with a dialogue system

The aim of this study was to investigate the influence of modality on collaboration processes between human and computer. Spoken and written interactions with a natural language dialogue system were compared using two real information-retrieval systems. In order to look for a restaurant (Experiment 1) or plan a trip (Experiment 2), participants performed several task-oriented dialogue scenarios. Although the spoken interaction mode was less efficient, it promoted collaboration, the use of personal pronouns and the literal form of the system's command utterances. Overall, in the written mode, the emphasis was on the task and its performance, rather than on dialogue. These findings are discussed with respect to the effect of communication mode on collaboration in human–computer dialogue.