対話を通じた情報獲得のための期待効用に基づく質問選択

抄録

We are developing a framework where a dialogue system asks questions for users and thus acquires information (cuisine of unknown restaurants) through dialogue. Such a question would be better if it is more concise and concrete. We propose a method to select an appropriate question on the basis of expected utility calculated for four question types: Yes/No, binary, ternary, and Wh- questions. We rst de ne utility for the four types by considering their appropriateness for users. We then de ne a probability that represents how likely a question contains a correct cuisine by using con dence measure (CM) of cuisine estimation. Then the sum totals of products of the utility and the probability are calculated as expected utility. As experiments, we compare several ways to integrate two basic CMs we proposed before. We also discuss adequacy of the utility values by using questionnaire results for 15 subjects.