Deep Web Queries in a Semantic Web Environment

Access to Deep Web sources is concerned with querying data that is hidden behind Web forms and primarily not accessible by common query languages. Web forms do not contain any type information, and it thus follows that Deep Web sources only work on string data in its rudimentary form. In this paper, we demonstrate how Semantic Web technologies can be used to first lift Deep Web sources to the level of databases with a precise schema and strong typing information and finally to the level of Semantic Web applications. A special focus in this context is on handling measurements, units and dimensions, which is an important issue when data from multiple Deep Web sources is declaratively combined for more involved querying tasks.