It’s time to get real with Linked Data. The World Wide Web Consortium’s Linked Data Platform Working Group, convened almost a year ago, is on the case, with expectations by June to publish a last call working draft of the specification, and to have a final recommendation, the last stage of the W3C’s standards process, by early next year.

“The Linked Data Platform is expanding on the concept [originally] put forward by Tim Berners-Lee on his web site, to turn it into a specification,” says Arnaud J. Le Hors, co-chair of the working group and IBM’s Linked Data Standards Lead. He will address the work at this session during next month’s SemTechBiz conference in San Francisco.

Why the need to formalize Linked Data?  While there is a fairly significant list of W3C standards around the Semantic Web, the more loosely-defined Linked Data has led to an environment where interoperability suffers. That’s because people are left to solve the same problems, such as those around publishing and retrieving data, over and over again, and they take different paths to get there, Le Hors says. The guides that are out there are just that, guides, with people free to use or ignore them, if they can even find them – which in itself isn’t easy to do for those who aren’t well-informed members of the community, he says.

The Linked Data Platform extends the model to provide the industry with a formal definition for read-write access to Linked Data; it mandates publishing data in a standard format, RDF, and using a standard protocol, HTTP, “which is completely symmetrical with the way the web works today, with HTML and HTTP,” Le Hors says.

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Mike Bergman recently asked the deceptively simple question, what do things mean on the semantic web? He explains, “The crowning achievement of the semantic Web is the simple use of URIs to identify data. Further, if the URI identifier can resolve to a representation of that data, it now becomes an integral part of the HTTP access protocol of the Web while providing a unique identifier for the data. These innovations provide the basis for distributed data at global scale, all accessible via Web devices such as browsers and smartphones that are now a ubiquitous part of our daily lives.” Read more

The W3C SPARQL Working Group has published updated drafts of the following SPARQL 1.1 documents.

• SPARQL 1.1 Query adds support for aggregates, subqueries, projected expressions, and negation to the SPARQL query language.
• SPARQL 1.1 Update defines an update language for RDF graphs.
• SPARQL 1.1 Service Description defines a vocabulary and discovery mechanism for describing the capabilities of a SPARQL endpoint.
• SPARQL 1.1 Uniform HTTP Protocol for Managing RDF Graphs describes the use of the HTTP protocol for managing named RDF graphs on an HTTP server.
• SPARQL 1.1 Entailment Regimes defines conditions under which SPARQL queries can be used with entailment regimes such as RDF, RDF Schema, OWL, or RIF.

The current plans of the Working Group are to publish the so called “Last Call” Working Draft around the end of the year.

The SPARQL Working Group has published a First Public Working Draft of SPARQL 1.1 Federation Extensions, which defines extensions to the SPARQL Query Language to support distributed SPARQL query execution. The group also published 5 updates, listed below. The group seeks feedback, particularly on open issues identified in each document.

• SPARQL 1.1 Query adds support for aggregates, subqueries, projected expressions, and negation to the SPARQL query language.
• SPARQL 1.1 Update defines an update language for RDF graphs.
• SPARQL 1.1 Service Description defines a vocabulary and discovery mechanism for describing the capabilities of a SPARQL endpoint.
• SPARQL 1.1 Uniform HTTP Protocol for Managing RDF Graphs describes the use of the HTTP protocol for managing named RDF graphs on an HTTP server.
• SPARQL 1.1 Entailment Regimes defines conditions under which SPARQL queries can be used with entailment regimes such as RDF, RDF Schema, OWL, or RIF.

I have often heard people lament the lack of federated systems in the Semantic Web. Certainly, the use of URIs allows data from many different sources to link together seamlessly, and the judicious use of assertions like owl:sameAs can help fill in the gaps, but if a developer wants to do something interesting with data from more than one SPARQL endpoint, they must draw it all in from various locations before merging and linking it all locally. Where is the "webiness" in this data? Wasn’t SPARQL supposed to do all of the processing work for us? Why do we need to do this work manually?

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Disclaimer:  This article does not reflect the views of the U.S. Environmental Protection Agency and does not constitute endorsement by the EPA of the standards or products mentioned.

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Last week’s announcement that HTTP PATCH has been adopted as an official verb via RFC 5789 has generated a lot of excitement (and questions). As a summary, the intention of each verb is:

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The W3C SPARQL Working Group has published a First Public Working Draft of SPARQL 1.1 Property Paths, which
defines a more succinct way to write parts of basic graph patterns and also extend matching of triple pattern to arbitrary length paths. The group also published six updates, namely:

• SPARQL 1.1 Query adds support for aggregates, subqueries, projected expressions, and negation to the SPARQL query language.
• SPARQL 1.1 Update defines an update language for RDF graphs.
• SPARQL 1.1 Protocol for RDF defines an abstract interface and HTTP bindings for a protocol to issue SPARQL Query and SPARQL Update statements against a SPARQL endpoint.
• SPARQL 1.1 Service Description defines a vocabulary and discovery mechanism for describing the capabilities of a SPARQL endpoint.
• SPARQL 1.1 Uniform HTTP Protocol for Managing RDF Graphs describes the use of the HTTP protocol for managing named RDF graphs on an HTTP server.
• SPARQL 1.1 Entailment Regimes defines conditions under which SPARQL queries can be used with entailment regimes such as RDF, RDF Schema, OWL, or RIF.

The W3C Evaluation and Repair Tools Working Group (ERT WG) has published new or updated a number of RDF vocabularies that are part of the Evaluation and Report Language (EARL). These working drafts include:

• Evaluation and Report Language (EARL) 1.0
• HTTP Vocabulary in RDF 1.0
• Representing Content in RDF 1.0
• Pointer Methods in RDF 1.0

See also the Evaluation and Report Language (EARL) 1.0 Guide.

EARL provides a format for expressing test results, such as those generated by Web accessibility evaluation tools, using a vendor-neutral and platform-independent format. While the review period has ended, ERT WG encourages you to review EARL 1.0 documents and submit any comments. See Call for Review: EARL 1.0 Last Call Working Draft e-mail for more information.

The W3C SPARQL Working
Group published the First Public Working Draft of six SPARQL 1.1
specifications. SPARQL is the query language of the Semantic Web, and
SPARQL 1.1 enhances the SPARQL landscape with:

• SPARQL 1.1
  Query – Adds support for aggregates, subqueries, projected
  expressions, and negation to the SPARQL query language.
• SPARQL 1.1
  Update – Defines an update language for RDF graphs.
• SPARQL 1.1
  Protocol – Defines an abstract interface and HTTP bindings for a
  protocol to issue SPARQL Query and SPARQL Update statements against a
  SPARQL endpoint.
• SPARQL 1.1
  Service Description – Defines a vocabulary and discovery mechanism
  for describing the capabilities of a SPARQL endpoint.
• SPARQL
  1.1 Uniform HTTP Protocol for Managing RDF Graphs – Describes the
  use of the HTTP protocol for managing named RDF graphs on an HTTP
  server.
• SPARQL 1.1
  Entailment Regimes – Defines conditions under which SPARQL queries
  can be used with entailment regimes such as RDF, RDF Schema, OWL, or
  RIF.