A Visual Technique for Web Pages Comparison

Despite the exponential WWW growth and the success of the Semantic Web, there is limited support today to handle the information found on the Web. In this scenario, techniques and tools that support effective information retrieval are becoming increasingly important. In this work, we present a technique for recognizing and comparing the visual structural information of Web pages, The technique is based on a classification of the set of html–tags which is guided by the visual effect of each tag in the whole structure of the page. This allows us to translate the web page to a normalized form where groups of html tags are mapped into a common canonical one. A metric to compute the distance between two different pages is also introduced. Then, by means of a compression process we are also able to reduce the complexity of recognizing similar structures as well as the processing time when comparing the differences between two Web pages. Finally, we briefly describe a prototype implementation of our tool along with several examples that demonstrate the feasibility of our approach.