TABOR - a norwegian spoken dialogue system for bus travel information

This paper describes the development and testing of a pilot spoken dialogue system for bus travel information in the city of Trondheim, Norway. The system driven dialogue was designed on the basis of analyzed recordings from both human-human operator dialogues, Wizard-of-Oz (WoZ) dialogues, and a text-based inquiry system for the web. The dialogue system employs a flexible speech recognizer and an utterance concatenation procedure for speech output. Even though the system is intended for research only, it has been accessible through a public phone number since October 1999. During this period all dialogues have been recorded. From these, approximately 350 dialogues were selected for annotation and comparison to 120 dialogues from the WoZ recordings. The experiments showed that the turn error rate was more than twice as large for the real dialogues as for the WoZ calls, i.e., 13.3% versus 5.7%. Thus, the WoZ results did not give a reliable estimate for the true performance. Our experiments indicate that the current flexible speech recognizer should be further optimized.