Unification in EL for Competency Question Generation

Competency Questions (CQs) are widely used in ontology development to represent the ontology requirements. Engineers can check if a CQ is satisfied manually or with software assistance. However, when a CQ is not satisfied, they need to analyze the axioms to discover what is missing. This activity may be hard and time-consuming, because of the size of the ontology and the complexity to inspect the axioms using inferences. In this paper, we present a method that uses unification in EL to generate new CQs based on an unsatisfied CQ. They are used to questioning an engineer, therefore she can provide answers to add the missing knowledge so as to satisfy the initial CQ to the ontology. We did two experiments using the SNOMED CT ontology. Our approach generated questions to add the missing knowledge in 69.09% cases.