Visual Queries over Scholarly Data and other Linked Data Endpoints 1 Kārlis Čerāns*, Lelde Lāce, Aiga Romāne, Jūlija Ovčiņņikova, Sergejs Kozlovičs 2 , Mikus Grasmanis, Jūlija Hodakovska, Artūrs Sproģis, Agris Šostaks Institute of Mathematics and Computer Science, University of Latvia *karlis.cerans@lumii.lv Abstract. We demonstrate the option to use the schema-based visual query tool ViziQuer over realistic Linked Data endpoints, with examples over the Semantic Web conference-related Scholarly Data. We present the pipeline of enabling vis- ual query creation over a SPARQL endpoint and ready-to-use data schemas over existing public Linked data endpoints, available in the ViziQuer Schema store. Keywords: Visual query tool, RDF data, SPARQL, Linked Data 1 Introduction Visual query composition (cf. [1], [2], [3], [4], [5]) along with facet-based ([6], [7]) and controlled natural language-based ([8]) approaches offers a promising avenue to enable end-user involvement in query composition over RDF/SPARQL data (cf. [1]). The recent version of ViziQuer notation ([5], [9]), implemented in a web-based tool 3 [10], allows for visual presentation of rich instance level and aggregate queries, involv- ing data expressions, as well as query nesting, with expressive power approaching that of the full SPARQL 1.1 [11]. Meanwhile, the currently available examples of the Vi- ziQuer notation and tool usage are largely related to in-house RDF data stores, not the publicly available Linked data sets that would be one of its primary usage targets. We shall report in this paper and present in the demonstration:  Visual query notation and tool usage examples over a public Linked Data end- point of Scholarly data 4 [12];  The pipeline of enabling visual query creation over a SPARQL endpoint, in- cluding a novel easy-to-use data schema extractor implementation;  Ready-to-use data schemas over existing public Linked data endpoints, avail- able in the ViziQuer Schema store (within the ViziQuer tool page). 1 Copyright © 2019 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). 2 Supported by ERDF project 1.1.1.2/VIAA/1/16/214 3 http://viziquer.lumii.lv/ 4 http://www.scholarlydata.org/