Sixth European Conference on Speech Communication and Technology

Budapest, Hungary
September 5-9, 1999

Mathematical Analysis of Dialogue Control Strategies

Yasuhisa Niimi, Takuya Nishimoto

Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Japan

In this paper we describe a quantitative relation between the efficiency of dialogue control strategies, we measure by the average number of exchanges taken during a dialogue, and the performance of a speech recognition system used in a spoken dialogue system. We consider four dialogue control strategies: (1) direct confirmation, (2) indirect confirmation, (3) multiple item answer followed by direct confirmations, and (4) multiple item answer followed by multiple item confirmations. If n information items are necessary to execute a task, a status of a dialogue is represented by a triplet (u; k; c) (u+k+c=n), where u, k and c are the numbers of unknown, known not yet confirmed, and confirmed items respectively. The mathematical analyses of the strategies are based on the fact that the state transition of a dialogue can be represented by a Markov process in which a space of states are a set of triplets (u; k; c), and state transition probabilities are decided by a speech recognition rate and user's behaviors.

Full Paper (PDF)   Gnu-Zipped Postscript

Bibliographic reference.  Niimi, Yasuhisa / Nishimoto, Takuya (1999): "Mathematical analysis of dialogue control strategies", In EUROSPEECH'99, 1403-1406.