Key points are not available for this paper at this time.
David Traum, Antonio Roque, Anton Leuski, Panayiotis Georgiou, Jillian Gerten, Bilyana Martinovski, Shrikanth Narayanan, Susan Robinson, Ashish Vaswani. Proceedings of the 8th SIGdial Workshop on Discourse and Dialogue. 2007.
Traum et al. (Mon,) studied this question.