The purpose of this study is to clarify the impact of the fact that “the information source is Wikipedia”on Japanese students’ credibility judgments of articles in encyclopedias. Six entries in Wikipedia Japanese edition and ENCYCLOPEDIA NIPPONICA JapanKnowledge edition were used as experiment objects. Entries with layout information and without layout information were prepared. The subjects were asked which entry was thought to be more accurate. Results revealed that subjects judged articles from Wikipedia Japanese edition were less accurate than articles from ENCYCLOPEDIA NIPPONICA when they had layout information. However subjects judged Wikipedia was more accurate than ENCYCLOPEDIA NIPPONICA when they did not have layout information. It was revealed that the fact that “the information source is Wikipedia” has big impact on Japanese students’ credibility judgments.

　This study examined the effectiveness of author verification in the “PC remote control virus” case. We compared nine anonymous texts, written in the series of the “PC remote control virus” case, with five control texts and several irrelevant texts. The control texts were the series written in the “nomaneko” case, the criminal, Mr. K, had been arrested and confessed before committing the “PC remote control virus” case. The irrelevant texts were written by ten bloggers of the same gender and age as Mr. K, and several letters claiming responsibility or threats in the past cases. We conducted hierarchical cluster analysis on the following aspects of writing style: (1) rate of usage of non-independent words, (2) trigram of parts-of-speech, (3) bigram of postpositional particles, and (4) bigram of characters. The results indicated that the anonymous nine texts were arranged identically or similarly to the clusters of the control texts, whereas they were arranged differently from each authorship cluster in the irrelevant texts. These results suggest that the texts written in both the “PC remote control virus” case and “nomaneko” case were written by same author.

　This is to report what was talked about and discussed in the session, “Seniors’ Round Table Meeting” given on March 1^st at Tsurumi-University, under the above title. During my working on the translation of a book on Wittgenstein and William James, I frequently visited the site of the WAB to make use of its database. I owe much to its open-access circumstances and its welldesigned system. Most of all my exegetic questions were solved. The Open-access to data-basis or sites of any kinds appears now to meet the world-wide tendencies and needs. But there, along with it, emerges another horizon of complicated ethical problems. The wider the space opens, the more its unknown corners would be darkened. The freer the way runs, the more slippery the road becomes. However, we must solve our problems one by one, anchoring in our reality, our own rough ground of human-being-ness as Wittgenstein advocated.