Users-groups matching in an annotation system: Ontological and URL relevance measures

The MADCOWannotation system supports a notion of group, facilitating focused annotations with respect to a domain. We argue that the use of an ontology to represent knowledge about the domain allows posting more refined annotations to a group, while the use of ontology concepts as tags facilitates the formulation of semantically significant queries for retrieving annotations on specific topics. Services for promoting participation to groups of potentially interested users can also leverage the adoption of domain ontologies, by matching tags users freely employed in their annotations to terms proper to some domain ontology. To this end, we propose a combination of existing relevance measures for matching users to domains.