Nowadays, data can be represented and stored by using different formats ranging from non structured data, typical of file systems, to semi-structured data, typical of Web sources, to highly structured data, typical of relational database systems. Therefore, the necessity arises to define new tools and models for uniformly handling all these heterogeneous information sources. In this paper we propose both a framework and a conceptual model which aim at uniformly managing information sources having different nature and structure for obtaining a global, integrated and uniform representation. We show also how the proposed framework and the conceptual model can be useful in many application contexts.
