Web Usage Mining: Information and Pattern Discovery on the World Wide Web Using Web Server Logs Amitha Caldera Abstract Web Mining is the extraction of interesting and potentially useful patterns from World Wide Web (WWW). Web Mining can be categorized into three areas of interest based on which part of the Web to mine: Web Content Mining, Web Structure Mining and Web Usage Mining. Web Content Mining is the discovery of useful information from the Web contents or documents. Web Structure Mining is the process of inferring knowledge from the hyperlink structure of the Web. Web Usage Mining is the discovery of interesting user access patterns from Web server logs. With the rapid progress of WWW technology, and the ever growing popularity of the WWW, the WWW continues to expand with over one billion connected users worldwide and over 800 million pages on many different subjects. Popular Web sites can see their Web server logs growing by hundreds of megabytes everyday. The major challenge involved in Web Usage Mining is pre-processing of raw server log data in the presence of caching and proxy servers to provide an accurate picture of how a site is being used. The results of the Web Usage Mining have become critical for number of applications such as Web site modification, system design improvement, server performance enhancement, business and marketing decision support. In my presentation, current practices of data pre-processing methods and their shortcomings, and the applications of data mining techniques to Web server logs in order to discover interesting access patterns will be discussed.