Moving Controlled Vocabularies into the Semantic Web

Abstract:

One of the issues with legacy oceanographic data formats is that the only tool available for describing what a measurement is and how it was made is a single metadata tag known as the parameter code. The British Oceanographic Data Centre (BODC) has been supporting the international oceanographic community gain maximum benefit from this through a controlled vocabulary known as the BODC Parameter Usage Vocabulary (PUV). Over time this has grown to over 34,000 entries some of which have preferred labels with over 400 bytes of descriptive information detailing what was measured and how.

A decade ago the BODC pioneered making this information available in a more useful form with the implementation of a prototype vocabulary server (NVS) that referenced each 'parameter code' as a URL. This developed into the current server (NVS V2) in which the parameter URL resolves into an RDF document based on the SKOS data model which includes a list of resource URLs mapped to the 'parameter'. For example the parameter code for a contaminant in biota, such as ‘cadmium in Mytilus edulis’, carries RDF triples leading to the entry for Mytilus edulis in the WoRMS and for cadmium in the ChEBI ontologies. By providing links into these external ontologies the information captured in a 1980s parameter code now conforms to the Linked Data paradigm of the Semantic Web, vastly increasing the descriptive information accessible to a user.

This presentation will describe the next steps along the road to the Semantic Web with the development of a SPARQL end point¹ to expose the PUV plus the 190 other controlled vocabularies held in NVS. Whilst this is ideal for those fluent in SPARQL, most users require something a little more user-friendly and so the NVS browser² was developed over the end point to allow less technical users to query the vocabularies and navigate the NVS ontology. This tool integrates into an editor that allows vocabulary content to be manipulated by authorised users outside BODC.

Having placed Linked Data tooling over a single SPARQL end point the obvious future development for this system is to support semantic interoperability outside NVS by the incorporation of federated SPARQL end points in the USA and Australia during the ODIP II project.

¹https://vocab.nerc.ac.uk/sparql

² https://www.bodc.ac.uk/data/codes_and_formats/vocabulary_search/