Discovering the Deep Web through XML Schema Extraction

The web accessible by the search engines contains a vast amount of information. However, there is another part of the web called the deep web accessible only through its associated HTML forms, and containing much more information. The integration of the deep web content presents many challenges that are not fully addressed by the actual deep web access approaches. The integration of the deep web data requires knowing the schema describing each deep web source. This paper presents our approach to extract the XML schema describing a selected deep web source. The XML schema extracted will be used to integrate the associated deep web source into a mediation system. The principle of our approach is to apply a static and a dynamic analysis to the HTML forms giving access to the selected deep web source. We describe the algorithms of our approach and compare it to the other existing approaches.