Representing the Hierarchy of Industrial Taxonomies in OWL: The gen/tax Approach

Existing taxonomies are valuable input for creating ontologies, because they reflect some degree of community consensus and contain, readily available, a wealth of concept definitions plus a hierarchy. However, the transformation of such taxonomies into useful ontologies is not as straightforward as it appears, because simply taking the hierarchy of concepts, which was originally developed for some external purpose other than ontology engineering, as the subsumption hierarchy using rdfs:subClassOf can yield useless ontologies. In this paper, we (1) illustrate the problem by analyzing OWL and RDF-S ontologies derived from UNSPSC (a products and services taxonomy), (2) detail how the interpretation and representation of the original taxonomic relationship is an important modeling decision when deriving ontologies from existing taxonomies, (3) propose a novel “gen/tax” approach to capture the original semantics of taxonomies in OWL, based on the split of each category in the taxonomy into two concepts, a generic concept and a taxonomy concept, and (4) show the usefulness of this approach by transforming eCl@ss into a fully-fledged products and services ontology.