A GRAPH-BASED FRAMEWORK FOR MULTIPARADIGMATIC VISUAL ACCESS TO DATABASES

We describe an approach for multiparadigmatic visual access to databas es, which is proposed to achieve seamless integration of different int eraction paradigms. The user is provided with an adaptive interface au gmented by a user model, supporting different visual representations o f both data and queries. The visual representations are characterized on the basis of the chosen visual formalisms, namely forms, diagrams, and icons. To access different databases, a unified data model, the Gr aph Model, is used as a common underlying formalism to which databases , expressed in the most popular data models, can be mapped. Graph Mode l databases are queried through the adaptive interface. The semantics of the query operations is formally defined in terms of graphical prim itives. Such a formal approach permits us to define the concept of ''a tomic query,'' which is the minimal portion of a query that can be tra nsferred from one interaction paradigm to another and processed by the system. Since certain interaction modalities and visual representatio ns are more suitable for certain user classes, the system can suggest to the user the most appropriate interaction modality as well as the v isual representation, according to the user model. Some results on use r model construction are presented.