Graphol: Ontology representation through diagrams

ABSTRACT. In this paper we present Graphol, a novel language for the diagrammatic representation of Description Logic (DL) ontologies. Graphol is designed with the aim of offering a completely visual representation to the users (notably, no formulae need to be used in our diagrams), thus helping the understanding of people not skilled in logic. At the same time, it provides designers with simple mechanisms for ontology editing, which free them from having to write down complex textual syntax. Graphol offers most of the classical constructs used in DLs, and allows for specifying expressive ontologies. It is also suitably extended to capture the same expressivity of OWL 2. In this respect, we developed a basic tool to translate Graphol ontologies realized with the yEd graph editor into OWL 2 encoding. User evaluation tests, conducted with designers skilled in conceptual or ontology modeling and users without specific logic background, demonstrate the effectiveness of our language for both visualization and editing of ontologies.