Workshop Report
2010-07-12: W3C has published the report, the meeting minutes of the plenary day, and the main findings of the Workshop. A separate work items summary table lists each of the possibilities discussed for a possible RDF Working Group, indicating the level of support expressed via a straw poll of the workshop participants. The Semantic Web community is asked to comment on these results using the Semantic Web Interest Group mailing list (and copied to the separate RDF Comments' list). Whether or not a new Working Group will be formed and, if yes, based on which technical items, will be decided after that community discussion.
Background
The Resource Description Framework (RDF), including the general concepts, its semantics, and an XML Serialization (RDF/XML), have been published in 2004. Since then, RDF has become the core architectural block of the Semantic Web, with a significant deployment in terms of tools and applications.
As a result of the R&D activities and the publication of newer standards like SPARQL, OWL, POWDER, or SKOS, but also due to the large scale deployment and applications, a number of issues regarding RDF came to the fore. Some of those are related to features that are not present in the current version of RDF but which became necessary in practice (eg, the concept of “Named Graphs”). Others result from the difficulties caused by the design decisions taken in the course of defining the 2004 version of RDF (eg, restrictions whereby literals cannot appear as subjects). Definition of newer standards have also revealed difficulties when applying the semantics of RDF (eg, the exact semantics of blank nodes for RIF and OWL, or the missing connection between URI-s and the RDF resources named by those URI-s for POWDER). New serializations formats (eg, Turtle) have gained a significant support by the community, while the complications in RDF/XML syntax have created some difficulties in practice as well as in the acceptance of RDF by a larger Web community. Finally, at present there is no standard programming API to manage RDF data; the need may arise to define such a standard either in a general, programming language independent way or for some of the important languages (Javascript/ECMAscript, Java, Python,…)
It is therefore time to consider whether a revision of the 2004 version of RDF is necessary or whether the community can continue developing with the current version.
Workshop Goals
The goal of the workshop is to gather feedback from the Web community on whether and, if yes, in which direction RDF should evolve. One of the main issues the Workshop should help deciding is whether it is timely for W3C to start a new RDF Working Group to define and standardize a next version of RDF.
While a new version of RDF may include changes in terms of features, semantics, and serialization syntax(es), backward compatibility is of a paramount importance. Indeed, RDF has been deployed by tools and applications, and the last few years have seen a significant uptake of Semantic Web technologies and publication of billions of triples stemming from public databases (see, eg, the Linked Open Data community). It would be, therefore, detrimental to this evolution if RDF was seen as unstable and if the validity of current application would be jeopardized by a future evolution. As a consequence, with any changes of RDF, backward compatibility requirements should be formalized, along the lines of, say:
- any valid RDF graphs (in terms of the RDF 2004 version) should stay valid in terms of a new version of RDF; and
- any RDFS entailment drawn on RDF graphs using the 2004 semantics should be valid entailement in terms of a new version of RDF
The main outcome of the workshop will be the publication of a workshop proceedings and, in case there is a consensus on moving forward, a draft for a charter for a newly created RDF Working Group.
Workshop Program
The first day of the program is a series of presentations, consisting of a selection of the accepted submissions. The second day is planned to consist of break-out groups addressing a particular topics of discussion. The list of discussion topic has been initially created based on all submissions; it is expected that this list will change during the first day of the event. For the detailed list of presentations, and the initial list of discussion topics, see the Wiki page of the event.
Participation
Submitters of positions papers to the Workshop, members of the Program Committee of the Workshop, member of the W3C Semantic Web Coordination Group are welcome to join at the Workshop. The Workshop Chairs may also decide to invite experts on an individual basis. Participants should put register via the separate Participants’ page
Accepted Submissions
- “Suggestions Toward RDF Semantics Improvement — Inspired by the Lexical Grid”, by Cui Tao, Jyotishman Pathak, Harold Solbrig, Wei-Qi Wei, and Christopher G. Chute
- “Flat triples approach to RDF Graphs in JSON”, by Dominik Tomaszuk
- “RDF Next Steps, Telefónica's Position Paper”, by José Manuel Cantera Fonseca
- “RDF: Back to the Graph”, by Peter F. Patel-Schneider
- “Name That Graph”, by Fabien Gandon and Olivier Corby
- “Supporting Change Propagation in RDF”, by Andy Seaborne and Ian Davis
- “Provenance Requirements for the Next Version of RDF”, by Jun Zhao, Christian Bizer, Yolanda Gil, Paolo Missier, and Satya Sahoo
- “RDF Needs Annotations”, by Nuno Lopes, Antoine Zimmermann, Aidan Hogan, Gergely Lukácsy, Axel Polleres, Umberto Straccia, and Stefan Decker
- “RDF and XML: Towards a Unified Query Layer”, by Nuno Lopes, Stefan Bischof, Orri Erling, Axel Polleres, Alexandre Passant, Diego Berrueta, Antonio Campos, Jé́rôme Euzenat, Kingsley Idehen, Stefan Decker, Sté́phane Corlosquet, Jacek Kopecky ́, Janne Saarela, Thomas Krennwallner, Davide Palmisano, and Michal Zaremba
- “RDF Syntaxes 2.0”, by David Beckett
- “Aspect-Oriented Data”, by Ora Lassila, Mika Mannermaa, Marwan Sabbouh, and Ian Oliver
- “RDF Isolation API”, by James Leigh and David Wood
- “An Ordered RDF List”, by James Leigh and David Wood
- “Redefining the RDFS Closure to be Decidable”, by Jesse Weaver
- “Using RDF for social information management”, by Axel Rauschmayer
- “Personal RDF”, by Thomas Lörtsch
- “What I Want in RDF 2.0”, by David Booth
- “OMG Ontology PSIG”, by Elisa Kendall, Roy Bell, Roger Burkhart, Manfred Koethe, Hugues Vincent, and Evan Wallace
- “When owl:sameAs isn’t the Same: An Analysis of Identity Links on the Semantic Web”, by Harry Halpin, Ivan Herman, and Patrick J. Hayes
- “Towards a minor revision of RDF”, by Jeremy Carroll
- “Revisiting Blank Nodes in RDF to Avoid the Semantic Mismatch with SPARQL”, by Marcelo Arenas, Mariano Consens, and Alejandro Mallea
- “Triplesets: Tagging and Grouping in RDF Datasets”, by Atanas Kiryakov and Vassil Momtchev
- “Next steps for RDF: Keep the core and pave the cowpaths”, by Richard Cyganiak
- “RDFS 3.0”, by James Hendler
- “Cambridge Semantics Position”, by Lee Feigenbaum
- “Contextualized RDF Importing”, by Jie Bao, Li Ding, and Deborah L. McGuinness
- “Atom on the Web of Data: The Activity Streams Example”, by Harry Halpin and Chris Messina
- “The Future of RDF”, by Tim Berners-Lee
Workshop Organization Committee
Workshop Chairs
- David Wood, Zepheira
- Stefan Decker, DERI
- Ivan Herman, W3C
Program Committee:
The program committee consists of:
- Chris Bizer, Free University Berlin
- Dan Brickley, Free University of Amsterdam
- Jeremy Carroll, Top Quandrant
- Paula Gearon, Mulgara/Duraspace
- Sandro Hawke, W3C
- Pat Hayes, Florida Institute for Human & Machine Cognition
- Ian Horrocks, University of Oxford
- James Leigh
- Péter Mika, Yahoo!
- Chimezie Ogbuji, Cleveland Clinic
- Andy Seaborne, Talis
- Chris Welty, IBM
Venue
Hosted by the National Center for Biomedical Ontology (NCBO), Stanford, CA, USA. See the separate page on hotels and the details of the venue.