The Wikipedia is a source of information widely used in homes, schools, and offices across California, and across the nation. The Wikipedia is also the most successful, and influential, example of collaborative content creation. Most Wikipedia articles can be edited by anyone. This openness has been a key factor in the success of the Wikipedia, but it also poses challenges. Rogue, misinformed, or misguided contributors can corrupt articles with incorrect information, and it is difficult for readers to judge the reliability of the information they are presented. We propose to develop a reputation system for Wikipedia authors, and to use the resulting author reputation to compute a trust value for the text of Wikipedia articles. The author reputation we compute can be used to limit access to critical or controversial articles to authors of good reputation. The trust value, computed for each word of each article, will enable readers to form an informed opinion on the reliability of the information. We will demonstrate our approach by building a mirror site of the English Wikipedia, where the article text is colored according to its trust value. The Wikimedia Board of Trustees2 has expressed interest in this project as part of the Board’s drive towards reliability and sustainability in the Wikipedia. We expect that the techniques we develop will be useful in a much wider context than the Wikipedia. Our research addresses the core issue of judging the trust value, and tracking the provenance and source reputation, for bodies of evolving information. This can be applied in any setting where information is gathered or created in an open, collaborative, or heterogeneous fashion.

2009 Update:

Open, world-scale collaboration is one of the most effective mechanisms for organizing knowledge and making it accessible. This is best demonstrated by the Wikipedia, an online encyclopedia that has grown via the collaboration and contributions of millions of users worldwide. The core challenges of open collaboration are incentives, and quality. How can we incentivate contributors? And if anyone can contribute, how can information quality be guaranteed? For instance, questions on information quality and reliability are the main limiting factor in the adoption of Wikipedia in schools nationwide and worldwide. WikiTrust built a reputation system for Wikipedia authors, and a trust system for Wikipedia content. The reputation system provides an incentive for long-lasting contributions; the trust system provides an intuitive, word-level guide to the extent with which Wikipedia content has been revised by reputable contributors. WikiTrust is scheduled to be adopted by the Wikimedia Foundation on the English Wikipedia in Summer / Fall 2009. Using WikiTrust, every Wikipedia visitor will be able to assess the origin of information in the Wikipedia: author, revision of origin, and degree of revision by high-reputation users. In particular, WikiTrust prevents malicious tampering with information on the Wikipedia, helping uncover any modi"cation that has not underwent su#cient review. WikiTrust will also be instrumental in compiling versions of Wikipedia that can be distributed in DVD or CD form to countries where internet access is still unreliable. In fact, WikiTrust can help select revisions of Wikipedia articles on the basis of their quality: this selection process, which has to take place for over 30,000 articles, is the main task involved in producing such DVD or CD releases of Wikipedia.
WikiTrust is collaborating with the Wikimedia Foundation on this project, which will benefit Wikipedia users worldwide, and in particular, users in schools and developing countries.