A Generic Approach for Representing Model-Based Superimposed Information

Superimposed information is used to supplement existing sources of information, while maintaining connections back to the original data. It can be used for organizing, highlighting, annotating, connecting, and reusing selected elements within information sources. With the growing amount of digital information available today, especially on the web, more and more applications are being developed that use superimposed information. However, generic support to store, create, update, and transform superimposed information does not exist. Superimposed applications must implement their own representation and storage capabilities, which also makes superimposed information difficult to share across applications. We seek to represent superimposed information for a wide variety of model-based applications (e.g., XML and CASE tools, Topic Map navigators, SQL, and even spreadsheet editors) that use superimposed information. Our solution leverages a metamodel that is used to define multiple superimposed-information models. We employ a flat representation scheme, using the Resource Description Framework, to represent models (defined by our metamodel), schemas, and instances of superimposed information. As a result, we are able to provide model-based applications with a uniform, generic representation of superimposed information. While the generic representation is stored explicitly, it need not be visible to an application, which we support through a variety of application programming interfaces. The APIs provide ease of use and rapid superimposed-application development. The representation also enables mappings between superimposed layers, which allows applications to dynamically share superimposed information.