Extraction of polarity comments from Nico Nico Douga

Abstract

In this paper, we propose two methods that extract polarity comments from Nico Nico Douga and analyse errors in these methods. For example, a positive comment is 'iine: good' and a negative comment is 'hetakuso: unskilled'. Online videos have become indispensable to people, with millions watching videos on video websites. Moreover, demand of video sites is increasing because internet election campaigns started in April 2013. We consider that polarity comments are useful for the analysis of internet election campaigns. Our methods achieved 99% and 65% precision for extracting positive and negative comments, respectively.