Discovering Web Pages Censored by Search Engines in Japan

Google is a popular search engine, however, there are some cases that search results are manipulated artificially by Google. In this paper, we develop a system of discovering semiautomatically the Web pages which are censored by Google in Japan. We also analyze the censored Web pages discovered by the system to find the tendency of censorship.The outline of discovering censored Web pages is as follows: The system compares the results of American and Japanese Google. If some Web page exists on the result of American Google but not on that of Japanese Google, the system decides by using search option whether this Web page is censored. The experiment in this paper discovers 169 Web pages censored by Japanese Google in 14 weeks.