Enhancing Web Portals with Ontology-Based Data Access: The Case Study of South Africa's Accessibility Portal for People with Disabilities

Web portal software is relatively easy to set up and populate from the perspective of the end-user, but it leaves the back-end database devoid of subject domain semantics due to the requirement for a generic implementation. This approach seriously hampers effective search capabilities to retrieve relevant information. Ontology-based data access (OBDA) could, in theory, solve this problem through adding a semantic ‘layer’ over such web portal implementations. To this end, we provide and demonstrate the proof-of-concept methodology by enhancing the operational National Accessibility Portal of South Africa. We developed the adolena ontology, which is based on both the semantics in the database and augmented with notions from foundational and related domain ontologies. adolena was then made compliant with the OWL2 profile DL-LiteA and mapped to the relational database using the OBDA Plugin for Protégé. Experimentation with OBDA queries unequivocally demonstrates its advantages compared to the portal’s keyword-based