Analyzing listeners' empathy by their nonverbal behaviors in Bibliobattle

Nonverbal information plays an important role to convey feelings and/or interests of the people in conversations. Since Bibliobattle, a book-review game, has pleasant features to investigate non-verbal information on conversation settings, we conduct a series of experiments on Bibliobattle settings. In Bibliobattle, each speaker presents his/her own recommended book to listeners as a bibliobattler in 5 minutes. At the end of all presentations, everyone votes for the champion book. We analyzed a series of Bibliobattle experiments by video investigation. In the analysis, we focused on the listeners’ non-verbal information, in particular, nods, laughs and change postures. Our results showed that there are co-occurrence of nonverbal action among the audience in Bibliobattles. The frequency of co-occurrence of positive non-verbal information were assumed to be excitement of the presentation. However, interestingly, the results showed that the frequency does not affect the result of voting for the champion book in Bibliobattle. We discuss the cause of the results in the paper.