Semantic Object Mapping using SHACL Validated Resource Graphs

Metadata describing research data is a core instrument for compliance with the FAIR Guiding Principles. RDF is very suitable for this purpose because its schema-lessness provides flexibility for changes and different disciplines. In order to follow defined metadata schemas, RDF needs to be restricted by application profiles. SHACL allows validating whether an RDF based metadata matches a certain shape and meets minimum quality requirements. Described research data hence becomes resources in a validated knowledge graph. Searchability is achieved by SPARQL, which, however, requires considerable technical knowledge. The presented semantic object mapping of validated resource graphs into an JSON object is an approach which is less dependent on the users' background. The evaluation was performed based on precision, recall and response times using Elasticsearch as a search engine on the mapped object in comparison to generated SPARQL queries. The results show that with the transformation of RDF based (meta-)data into a search index using application profiles and inference rules, a solution was found that is equivalent in these terms. Through the integration of the developed mapping in the data management platform Coscine, a search of the research data is possible which at the same time promotes the subsequent use.