Publication Date

September 2005

Document Type



As a priority-setting exercise, we compared interactions between users and a simple spoken dialog system to interactions between users and a human operator. We observed usability events, places in which system behavior differed from human behavior, and for each we noted the impact, root causes, and prospects for improvement. We suggest some priority issues for research, involving not only such core areas as speech recognition and synthesis and language understanding and generation, but also less-studied topics such as adaptive or flexible timeouts, turn-taking and speaking rate.