Formulating unambiguous queries in the Semantic Web applications is a challenging task for users. This article presents a new approach in guiding users to formulate clear requests based on their common nature of querying for information. The approach known as the front-end approach gives users an overview about the system data through a virtual data component which stores the extracted metadata of the data storage sources in the form of an ontology. This approach reduces the ambiguities in users’ requests at a very early stage and allows the query process to effectively perform in fulfilling users’ demands in a context-aware manner. Furthermore, the approach provides a powerful query engine, called context-aware querying, that recommends the appropriate query patterns according to the user’s querying context.
Research activities in ontology-based search/query systems could be classified in to variant categories (Hoang & Tjoa, 2006). In this section we only present two related issues: (a) ontology-enhanced search strategies and (b) query formulation.