Modeling User Satisfaction Transitions in Dialogues from Overall Ratings.

This paper proposes a novel approach for predicting user satisfaction transitions during a dialogue only from the ratings given to entire dialogues, with the aim of reducing the cost of creating reference ratings for utterances/dialogue-acts that have been necessary in conventional approaches. In our approach, we first train hidden Markov models (HMMs) of dialogue-act sequences associated with each overall rating. Then, we combine such rating-related HMMs into a single HMM to decode a sequence of dialogue-acts into state sequences representing to which overall rating each dialogue-act is most related, which leads to our rating predictions. Experimental results in two dialogue domains show that our approach can make reasonable predictions; it significantly outperforms a baseline and nears the upper bound of a supervised approach in some evaluation criteria. We also show that introducing states that represent dialogue-act sequences that occur commonly in all ratings into an HMM significantly improves prediction accuracy.