Enabling text search on SPARQL endpoints through OSCAR

In this paper we introduce the latest version (Version 2.0) of OSCAR, the OpenCitations RDF Search Application, which has several improved features and extends the query workflow comparing with the previous version (Version 1.0) that we presented at the workshop entitled Semantics, Analytics, Visualisation: Enhancing Scholarly Dissemination (SAVE-SD 2018), held in conjunction with The Web Conference 2018. OSCAR is a user-friendly search platform that can be used to search any RDF triplestore providing a SPARQL endpoint, while hiding the complexities of SPARQL, thus making the search operations accessible to those who are not experts in Semantic Web technologies. We present here the basic features and the main extensions of this latest version of OSCAR. In addition, we demonstrate how it can be adapted to work with different SPARQL endpoints containing scholarly data, using as examples the OpenCitations Corpus (OCC) and the OpenCitations Index of Crossref open DOI-to-DOI citations (COCI), both provided by OpenCitations, and also the Wikidata dataset provided by the Wikimedia Foundation. We conclude by reporting the usage statistics of OSCAR, retrieved from the OpenCitations website logs, so as to demonstrate its uptake.