WebMaster: Knowledge-Based Verification of Web-Pages

Maintaining contents of Web sites is an open and urgent problem on the current World Wide Web as well as on company intra-nets. Although many current tools deal with problems such as broken links and missing images, very few solutions exist for maintaining the contents of Web sites and intra-nets. We present a knowledge-based approach to the verification of Web-page contents. The user exploits semantic markup in Webpages to formulate rules and constraints that must hold on the information in a site. An inference engine subsequently uses these rules to categorise Web-pages in an ontology of pages, while the constraints are used to define categories of pages which contain errors. We have constructed WebMaster, a software tool for knowledge-based verification of Web-pages. WebMaster allows the user to define rules and constraints in a graphical format, and is then able to use these rules to detect outdated, inconsistent and incomplete information in Web-pages. In this paper, we describe the various options for semantic markup on the Web, we define a precise logical and graphical format for rules and constraints, and we report on our practical experiences with WebMaster. Acknowledgements The work reported in this paper has only been possible with the contributions from all current and past members of the WebMaster team at AIdministrator: Jan Bakker, Chris Fluit, Herko ter Horst, Walter van Iterson, Arjohn Kampman and Gert-Jan van de Streek. Part I: “The business issue”