Constraining user response via multimodal dialog interface

This paper presents the results of an experiment comparing two different designs of an automated dialog interface. We compare a multimodal design utilizing text displays coordinated with spoken prompts to a voice-only version of the same application. Our results show that the text-coordinated version is more efficient in terms of word recognition and number of out-of-grammar responses, and is equal to the voice-only version in terms of user satisfaction. We argue that this type of multimodal dialog interface effectively constrains user response to allow for better speech recognition without increasing cognitive load or compromising the naturalness of the interaction.