Providing the Semantic Layer for WIS Design

Designing Web-based information systems requires the use of a thorough design methodology. Particularly, when the content of the system is gathered from different information sources available via the Web, the specification of how data is to be retrieved requires appropriate design tools. Concretely, a solution to the problem of how to facilitate the design of integrating heterogeneous information sources is needed, in order to be able to provide a uniform access to data gathered from different sources. In this paper we propose the use of the Hera methodology extended with the Semantic Layer, which concentrates on the integration aspect. The presented integration framework provides a coherent and meaningful (with respect to a given conceptual model) view of the integrated heterogeneous information sources.