Entropy-Based Metrics for Evaluating Schema Reuse

Schemas, which provide a way to give structure to information, are becoming more and more important for information integration. The model described here provides concrete metrics of the momentary "health" of an application and its evolution over time, as well as a means of comparing one application with another. Building upon the basic notions of actors, concepts, and instances, the presented technique defines and measures the information entropy of a number of simple relationships among these objects. The technique itself is evaluated against data sets drawn from the Freebase collaborative database, the Swoogle search engine, and an instance of Semantic MediaWiki.