Editorial

This final issue 6 of the year 2015 contains 3 regular submissions, which brings the total number of published papers (not counting editorials) in 2015 to 35. At the same time, this marks the second year in which we have published six issues, rather than four. Given the still increasing number of high-quality submissions, and to ensure timely publication, we will continue with six issues for 2016.

The first paper in this issue, Semantic technologies for historical research: A survey, by Albert Meroño-Peñuela, Ashkan Ashkpour, Marieke van Erp, Kees Mandemakers, Leen Breure, Andrea Scharnhorst, Stefan Schlobach and Frank van Harmelen is a survey article. It revisits joint work by historians and computer scientists on the use of Semantic Web technologies in the context of historical research and the handling of information relevant for said research.

The second paper, A logical characterisation of SPARQL federation, by Audun Stolpe is a regular research paper. It presents the author’s work towards a formal framework for reasoning about distributed query processing in SPARQL.

Finally, the third paper, Link traversal querying for a diverse Web of Data, by Jürgen Umbrich, Aidan Hogan, Axel Polleres and Stefan Decker is a regular research paper as well. It studies the recall and effectiveness of link-traversal based query execution over the web of data.