Mediatory Summary Generation: Summary-Passage Extraction for Information Credibility on the Web

In this paper, we discuss the summarization for supporting a user’s judgment on the credibility of information on the Web. In general, if a statement contradicts another statement, the credibility of either of the statements decreases. However, these opposing statements may coexist under certain situations, and presenting such situations is helpful for a user’s judgment. Therefore, we focus on the coexistence of these opposing statements, and attempt to develop a system to generate survey reports that contain mediatory summaries, which are defined as passages extracted from Web documents in order to present situations in which these opposing statements can coexist. We describe the outline of the summarization system and describe how to improve the TextRank algorithm from the viewpoint of passage extraction for the system. From experimental results, we confirmed that the methods based on the improved TextRank algorithm can extract significant passages, which are actually considered as significant by human assessors, with higher precision than baseline methods.