Linked Open Data and Ontology Infrastructure for Second World War History

Data about the Second World War (WW2) is heterogeneous and distributed in different organizations and countries. This paper argues that in order to create aggregated global views of the war, a shared semantic infrastructure is needed, including data models of the real world events, metadata schemas for presenting their documentation, a data harmonization model for data aggregation, and shared domain ontologies for populating the schemas in an interoperable way. As a solution, a Linked Open Data service is presented for publishing data about Finland in WW2. The service is based on W3C Semantic Web standards and best practices, including content negotiation, SPARQL API, download, automatic documentation, and other services supporting re-use of the data. The ontologies and data in the service, totalling ca. 9 million triples, is in use in seven end-user applications of the WarSampo portal, that have had tens of thousands of end-users.