With the emergence of the World Wide Web, business’ databases are increasingly being queried directly by customers. The customers may not be aware of the exact structure of the underlying data, and might have never learned a query language that enables them to issue structured queries. Some of the employees who query the databases may also not be aware of the structure of the data, but they are likely to be aware of some labels of elements containing the data. There is a need for a dual search engine that accommodates both business employees and customers. We propose in this chapter an XML search engine called SEEC, which accepts Keyword-Based queries (which can be used for answering customers’ queries) and Loosely Structured queries (which can be used for answering employees’ queries). We proposed previously a stand-alone Loosely Structured search engine called OOXSearch (Taha & Elmasri, 2007). SEEC integrates OOXSearch with a Keyword-Based search engine and uses novel search techniques. It is built on top of an XQuery search engine (Katz, 2005). SEEC was evaluated experimentally and compared with three recently proposed systems: XSEarch (Cohen & Mamou & Sagiv, 2003), Schema Free XQuery (Li & Yu & Jagadish, 2004), and XKSearch (Xu & Papakonstantinou, 2005). The results showed marked improvement.
