The goal of the Semantic Web initiative is as broad as that of the Web: to create a universal medium for the exchange of data. It is envisaged to smoothly interconnect personal information management, enterprise application integration, and the global sharing of commercial, scientific and cultural data. Facilities to put machine-understandable data on the Web are quickly becoming a high priority for many organizations, individuals and communities.
The Web can reach its full potential only if it becomes a place where data can be shared and processed by automated tools as well as by people. For the Web to scale, tomorrow's programs must be able to share and process data even when these programs have been designed totally independently. The Semantic Web Activity is an initiative of the World Wide Web Consortium (W3C) designed to provide a leadership role in defining this Web. The Activity develops open specifications for those technologies that are ready for large scale deployment, and identifies, through open source advanced development, the infrastructure components that will be necessary to scale in the Web in the future.
The principal technologies of the Semantic Web fit into a set of layered specifications. The current components are the Resource Description Framework (RDF) Core Model, the RDF Schema language, the Web Ontology language (OWL), and the Simple Knowledge Organization System (SKOS). Building on these core components is a standardized query language, SPARQL (pronounced "sparkle"), enabling querying decentralized collections of RDF data. The POWDER recommendations provide technologies to find resource descriptions for specific resources on the Web; descriptions which can be “joined” to other RDF data. The GRDDL and RDFa Recommendations aim at creating bridges between the RDF model and various XML formats, like XHTML. RDFa also plays an important role as a format to add Structured Data to HTML, i.e., as a means to help using Linked Data in Web Applications. The goal of the R2RML language is to provide standard language to map relational data and relational database schemas to RDF and OWL. Finally, the goal of the newly proposed Linked Data Profile Working Group is to provide a “entry level” layer to manage Linked Data file using RESTful, HTTP based API.
The RDF Working Group
has begun its work in February 2011. The The mission of the group is to update the
2004 version of the Resource
Description Framework (RDF) Recommendation. The group has published two
First Public Working Drafts: “Turtle
Terse RDF Triple Language” and “RDF
1.1 Concepts and Abstract Syntax”; the Turtle document is close to be
published as a Last Call document. Among its other chartered activities, the group
has found a satisfactory solution for issues around Literals, and its main focus
is currently on finding a proper formalization and semantics for graph
identification.
The RDF Working Group was also chartered to consider a JSON based serialization of RDF, as a means to bring these two communities further. After internal discussions it was decided that the RDF Working Group may not have the right expertise (due to the fact that it does not have Javascript and JSON developers in its midst); the JSON related work has now been spun off into a separate “JSON for Linking Data” Community Group, whose work is based on the upcoming JSON-LD specification; that group is now close to what could be considered as a “Last Call”. It is not yet decided, at this point, whether this specification will come “back” to the RDF group for final standardization, or whether a separate Working Group will be proposed for that.
The SPARQL Working Group has published a 2nd
Last Call on a number of documents in January 6. Some technical issues
surfaced (related to property paths) which delayed entering in Candidate
Recommendation phase. As a result of the discussion, a new
round of Last Calls were published. In view of a significant number of
implementations available already, the group may decide to skip the Candidate
Recommendation phase and go ahead with a Proposed Recommendation request instead.
The RDB2RDF Working Group is
now in Candidate Recommendation phase with both of its Recommendation Track
documents, namely the Direct
Mapping and R2RML.
This period should end April 30th.
As announced
on the 24th of January, the charter of the RDFWA
Working Group has been extended until the end of July. This announcement
also indicated that the group will not complete its work on the RDFa
API, due to missing manpower and the increased work on RDFa that came about
after the contacts with schema.org (also including the comments of the HTML Data
Task Force, see below). Instead, the group added a new document to the RDFa suite
of document, namely RDFa
1.1 Lite: a minimal subset of RDFa, consisting of only a few (RDFa)
attributes, but which cover the day-to-day needs of most of the authors of RDFa.
The three documents (RDFa
Core 1.1, XHTML+RDFa
1.1, and RDFa
1.1 Lite) are now in Proposed Recommendation, which is to end on the 5th of
June.
Related to the schema.org discussions, the Semantic
Web Interest Group started two task forces in fall 2011: the Web
Schemas Task Force, that looks at the vocabulary evolution, and the HTML
Data Task Force, whose goal was to provide a technical analysis on the
relationship of microdata, microformats, and RDFa, with possible change proposals
on the W3C specifications. In January 2012, the HTML Data Task Force has published
two notes: the HTML Data Guide,
which compares the various formats for structured data in HTML, providing advices
to authors, and the Microdata to
RDF document, that provides an algorithm to extract microdata from an HTML
page and turn it into RDF. (Note that the Microdata to RDF algorithm replaces the
algorithm that was part of an earlier draft of the Microdata specification and is
now removed from the latest
Microdata draft, published by the HTML Working Group.) After these
publications the Task Force was closed. The Web
Schemas Task Force, on the other hand, has become the
major public discussion forum for the evolution of schema.org vocabularies, and we
envisage keeping this task force open for the coming period.
The Provenance Working
Group has begun its work in April 2011. The mission of the Provenance
Working Group is to support the widespread publication and use of provenance
information of Web documents, data, and resources. It has published several drafts
of the Provenance Ontology Documents, the latest versions having been published
in May 2012. The group plans to issue a Last Call for these document in fall
2012.
The Semantic Web Health Care and Life
Sciences Interest Group (HCLSIG) has had a charter renewal, started
in August 2011, which ended successfully in September
2011. Since early September the group operates under its new
charter.
The Activity organized a successful Workshop on “Linked
Data Patterns for Implementation Applications on the World Wide Web”, in
December 2011. The goal of the Workshop was to understand what requirements and
challenges Linked Data technologies have when using them in an enterprise
environment, what are the areas that might require W3C’s attention for future work
in that area. The results of the workshop, as well as the subsequent discussions
with the community, led to the latest
Activity Proposal on the creation of a new Working Group, namely the Linked
Data Platform Working Group. The goal of this group is to define an “entry
level” set of RESful APIs to develop simpler Linked Data Applications that may
include large scale Enterprise Integration or Web Applications based on Linked
Data. More extensive Linked Data applications can then be built using other
elements of the stack, including RDFS,
SPARQL, OWL,
RIF, and the PROV
provenance vocabulary. The group has been approved, and a Call
for Participation has been sent to members, on the 9th of May; the group is
planning to be fully operational on the 1st of June.
Both the OWL Working Group and the Rule Interchange Format (RIF) is kept in a “dormant” state. The reason is that both the OWL2 and the RIF Recommendation will have to be re-issued when the XSD 1.1 document becomes a standard; the documents can then normatively refer to the XSD 1.1 Datatypes (which is not the case today). The XSD 1.1 Datatypes have been published as a Recommendation in April 2012, and the two groups plan to complete this work, and issue edited Recommendations, during the summer of 2012. No substantial change on OWL2 and RIF are planned, though.
The coming period should see the publication of several Recommendations, namely RDFa, RDB2RDF and, possibly before the next AC committee meeting, SPARQL 1.1. This also means that the activity of these groups will wind down and, eventually, close. This frees the activity to concentrate on the new Linked Data Platform Working group (in case of a successful vote of the Advisory Committee on the Activity Proposal), as well as consider some other areas of importance. This may include access control issues on Linked Data, Linked Data Publishing patterns, constraint checking on RDF data, as well as relationships to other communities like Libraries.
Summary of Activity Structure:
| Group | Chair | Team Contact | Charter |
|---|---|---|---|
| OWL Working Group (participants) |
Ian Horrocks, Alan Ruttenberg | Sandro Hawke, Ivan Herman | Chartered until 31 December 2012 |
| SPARQL Working
Group (participants) |
Lee Feigenbaum, Axel Polleres | Sandro Hawke | Chartered until 30 June 2012 |
| Rule
Interchange Format Working Group (participants) |
Christian de Sainte Marie, Christopher Welty | Sandro Hawke | Chartered until 31 December 2012 |
| RDF Web Applications
Working Group (participants) |
Ben Adida, Manu Sporny | Ivan Herman | Chartered until 31 July 2012 |
| Semantic Web
Coordination Group (participants) |
Ivan Herman | Ivan Herman | Chartered until 28 February 2013 |
| Semantic Web Health Care and Life Sciences Interest Group | Michel Dumontier, Charles Mead, Vijay Bulusu | Eric Prud'hommeaux | Chartered until 31 August 2014 |
| Semantic Web Interest Group | Dan Brickley | Ivan Herman | Chartered until 28 February 2013 |
| RDB2RDF Working
Group (participants) |
Ashok Malhotra, Michael Hausenblas | Ivan Herman, Eric Prud'hommeaux | Chartered until 30 September 2012 |
| RDF Working Group (participants) |
David Wood, Guus Schreiber | Sandro Hawke, Ivan Herman | Chartered until 31 January 2013 |
| Provenance Working
Group (participants) |
Luc Moreau, Paul Groth | Sandro Hawke | Chartered until 1 October 2012 |
This Activity Statement was prepared for AC 2012 per section 5 of the W3C Process Document. Generated from group data.
Ivan Herman, Semantic Web Activity Lead$Id: Activity.html,v 1.414 2011/09/09 01:35:33 ijacobs
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