Question selection based on expected utility to acquire information through dialogue

Abstract

We have been developing amethod for a dialogue system to acquire information (e.g., cuisines of unknown restaurants) through dialogue by asking questions of the users. It is important that the questions are concise and concrete to prevent users from being annoyed. Our method selects the most appropriate question on the basis of expected utility calculated for four types of question: Yes/No, alternative, 3- choice, and Wh- questions. We define utility values for the four types and also derive the probability representing how likely each question is to contain a correct cuisine. The expected utility is then calculated as the sum totals of their products. We empirically compare several ways to integrate two previously proposed basic confidence measures (CMs) when deriving the probability for each question. We also examine the appropriateness of the utility values through questionnaires administered to 15 participants.