“…An example of such application is the presentation of summaries by search engines; • Extraction of Keywords from Web Pages: A keyword is a word or a set of words which characterizes the content of a web page or site, and is used by users in their search process. Using content and usage information from a web page/site, we can extract/identify keywords which attract and retain users (Velasquez, & Palade, 2008); • Web Page Ranking: Hyperlinks can be used to rank web pages, in accordance with the interest of the user, such as in search engines (Page, Brin, Motwani, & Winograd, 1999); • Web Caching Improvement: Access patterns extracted from web logs can be used to extend caching policies in order to improve the performance of web accesses (Bonchi, Giannotti, Gozzi, Manco, Nanni, Pedreschi, Renso, & Ruggieri, 2001); • Clickstream and Web Log Analysis: The access logs can also be used to perform other types of analyses, from simple access statistics to user behavioral patterns, that help to improve the quality of web sites (Spiliopoulou, & Pohle, 2001;Joshi, Joshi, & Yesha, 2003); • Analysis of Web Site Topology: Web content and hyperlinks are used to analyze the topology of a web site and improve its organization, possibly reducing the number of alternative pages/hyperlinks that must be considered when we browse a web site (Wookey, & Geller, 2004); • Identifying Hubs and Authorities: Hyperlinks can also be used to identify hubs (directory pages) and authorities (popular pages) (Chakrabarti, Dom, Kumar, Raghavan, Rajagopalan, Tomkins, Gibson, & Kleinberg, 1999). A hub is a page that points to many other pages.…”