OntoMeter: Metrics for Ontologies

aintenance alternatives, and possibly 4. motivate interest groups to help improve currently weak segments of the ontology. Ontology Metrics Except for the raw number of classes and properties, there are no general, easily ascertainable indicators that help assess the content quality of an ontology. The mere number of those two constructs alone, however, is a poor indicator of the actual quality. Both reflect only the size of an ontology, but ignore - the actual coverage of relevant meaning, - the degree of order and structure, - and the amount of constraints and assertions that make concepts more specific. The following is a tentative list of metrics categories that are being evaluated: 1. Metrics for size (e.g. number of classes, number of properties, and lines of OWL code) 2. Metrics for structure (e.g. distribution of subclasses along the top-level classes) 3. Metrics for terminology precision (e.g. number of subclasses per toplevel class, weighted by the depth of branchi