Interfacing CLARIN with H2IOSC: Metadata Interoperability through Ontology-based Mediation

We present an ontology-based approach for integrating CLARIN language resources into the H2IOSC semantic framework, promoting interoperability across the Social Sciences and Humanities. Building on CMDI and the CLARIN Concept Registry, our work extends CMD2RDF beyond syntactic conversion to formal semantic integration. CMDI metadata is mapped to CIDOC CRM and SSHOCro, with extensions for CLARIN-specific needs. This ontology-first strategy keeps CMDI fully operational while ensuring theoretical consistency and long-term sustainability. The resulting semantic layer enhances discoverability, enables cross-disciplinary integration, and contributes to a scalable knowledge graph aligned with FAIR principles and the EOSC vision.