Okkam4P: A Protégé Plugin for Supporting the Re-use of Globally Unique Identifiers for Individuals in OWL/RDF Knowledge Bases

In Protégé, any newly created RDF/OWL knowledge base refers to local instances through a local URI, which is obtained through the concatenation of the ontology URI, the hash sign # and a local identifier. However, this practice makes data-level integration quite hard, and definitely prevents the straightforward application of RDF graph merging for independently developed knowledge bases, even if they share the same OWL ontology. In this paper, we present a Protégé plugin which supports the systematic reuse of global identifiers for instances in RDF/OWL knowledge base. The plugin is an extension of the Protégé “Individuals” tab. The main difference is that, when an instance is created, the user has a chance of looking for an existing URI for the corresponding individual in a publicly available service called Okkam. The match between the newly created instance and the globally registered individuals is based on a comparison of features of the new and a a simple profile stored in Okkam for all individuals. The plugin is available and tested for Protégé 3.3.1 and 3.4 beta.