Unnecessary utterance detection for avoiding digressions in discussion

In this paper, we propose a method for avoiding digressions in discussion by detecting unnecessary utterances and having a dialogue system intervene. The detector is based on the features using word frequency and topic shifts. The performance (i.e. accuracy, recall, precision, and F-measure) of the unnecessary utterance detector is evaluated through leave-one-dialogue-out cross-validation. In the evaluation, we find that the performance of the proposed detector is higher than that of a typical automatic summarization method.