I have had several posts in the past on the new features of RDFa 1.1 and where it adds functionalities to RDFa 1.0. The Working Group has just published a first draft for an RDFa 1.1 Primer , which gives an introduction to RDFa. We did have such a primeralready for RDFa, but the new version has been updated in the spirit of RDFa 1.1… Check it out if you are interested in RDFa!

Filed under: Semantic Web , Work Related Tagged: RDF , RDFa , Semantic Web , w3c

The RDF Web Applications Working Group has published a new Working Draft of the RDFa API . This document specifies an API to access the RDF data embedded in an HTML or XHTML page using RDFa. The Working Group also published a First Public Working Draft of the RDFa 1.1 Primer ; this is an updated version of the RDFa Primer that has been adapted to the features of RDFa Core 1.1specification.

The RDF Web Applications Working Group has published a new Working Draft of the RDFa API . This document specifies an API to access the RDF data embedded in an HTML or XHTML page using RDFa. The Working Group also published a First Public Working Draft of the RDFa 1.1 Primer ; this is an updated version of the RDFa Primer that has been adapted to the features of RDFa Core 1.1 specification. Learn more about the Semantic Web Activity.

This is just an extended tweet… Masahide Kanzaki has just posted an announcement on the LOD mailing list on releasing some data he collected on the radioactivity levels on different places in Japan, enriched with metadata (e.g., geo data or time). Though the original data were in PDF, the results are integrated in RDF with a SPARQL endpoint. He also added some visualization endpoint that gives a simple visualization of the SPARQL query results:

Simple but effective, and makes the point on the usage of open data in RDF… Thanks!

Filed under: Semantic Web , Work Related Tagged: Linked Open Data , Resource Description Framework , SPARQL

The RDF Working Group held its first face-to-face meeting on 13 & 14 April in Amsterdam. After two months of elaborate discussions the WG used this meeting to focus on the task it is chartered to do, namely updating RDF to meet the established practice of RDF usage. Interested readers can find detailed minutes of the discussions on the meeting page. A synopsis of the highlights:

• The WG expects to publish a First Public Working Draft of a Turtle recommendation in about two months. We resolved several issues w.r.t syntactic details of Turtle. The Turtle document is likely to include a separate section/appendix on N-Triples as a limited subset of Turtle. N-Triples is typically used as a dump format for triples. We also discussed a quadruple extension of Turtle (with a separate media type), but we refrained from deciding on syntactic details until the issues mentioned under the next item have been resolved.
• The WG concluded that the meaning of the term "graph" is overloaded. For the moment the WG has identified three different notions of "graph" (see the graph terminology page) for which we still have to find adequate labels. The current terms, "g-box" (a graph container, the contents of which may change over time), "g-snap" (a snapshot of a g-box at some point in time) and "g-text" (a serialization of a graph in, for example, Turtle or RDF/XML) are just placeholders. We discussed which notions of graphs could/should have identifiers. We discussed intensively how the three graph notions relate to the use of the term graph in the SPARQL specifications (in general, consistency with SPARQL is a major concern of the WG). We expect this to lead to a revised version of the 2004 RDF Concepts document. We also discussed implications for the RDF Semanticsdocument which we hope to be minimal (maybe even zero).
• Publication of a JSONformat for RDF gave rise to large amounts of email traffic in the first two months of the WG. We identified three use cases for a JSON-RDF syntax.
  The first use case is exemplified by the Talis JSONformat. This JSON format mimics the RDF graph structure in the JSON syntax. This format is mainly useful for developers already familiar with RDF. The WG decided that it is useful and feasible to publish such a format as a W3C recommendation, taking the Talis proposal as starting point.
  The second use case deals with the situation where one wants to expose RDF data to JavaScript developers in JSON format. An example of this can be found in the Linked Open Data API, and also in the way BBC and the NY Times make their data available as JSON. The WG feels it is not in a position (yet) to standardize this, but plans to publish a Note about current practices in the form of recipes, based on the available examples, to help developers who face a similar problem.
  The third use case is the most challenging one: providing a simple JSON object-format which general Web developers can use to expose their data and which subsequently can be consumed by RDF tools. JSON-LDis an example of this approach. The idea is that Web developers do not need to be aware of the RDF triple model when exposing their data. Such a JSON format could have a very high impact. Unfortunately, we do not seem to have enough insight yet into the issues involved to standardize this or define best-practices for it. For the moment, we want to treat this as a high-potential incubator activity and plan to revisit the situation at a later stage of the WG life time (and hopefully publish something by that time).

In addition, we discussed a number of "clean-up" issues. The WG is likely to mark some parts of the 2004 RDF vocabulary as "archaic" (meaning: we have no intention of removing these, but advise refraining from usage in the future), but details of this still need to be agreed on at a later stage.

As chair I was in particular happy with the open and constructive atmosphere in which the discussions took place. The results of the WG are not likely to shake the Web world, but will hopefully contribute significantly to enhanced and widespread effective use of Semantic Web technology.

The RDF Working Group has a public comment list. We welcome any feedback from the community.

18 months ago, when Ivan Herman and I began to plan a new RDF Working Group, I posted my RDF 2 Wishlist. Some people complained that the Semantic Web was not ready for anything different; it was still getting used to RDF 1. I clarified that “RDF 2″ would be backward compatible and not break existing system, just like “HTML 5″ isn’t breaking the existing Web. Still, some people prefered the term “RDF 1.1″.

The group just concluded its first face-to-face meeting, and I think it’s now clear we’re just doing maintenance. If we were to do version numbering, it might be called “RDF 1.0.1″. This might just be “RDF Second Edition”. Basically, the changes will be editorial clarifications and bug fixes.

The adventurer in me is disappointed. It’s a bit like opening your birthday present to find nice warm socks, instead of the jet pack you were hoping for.

Of course, this was mostly clear from the workshop poll and the charter, but still, I had my hopes.

The most dramatic change the group is likely to make: advise people to stop using xs:string in RDF. Pretty exciting. And, despite unanimous support from the 14 people who expressed an opinionin the meeting, there has now been some strong pushback from people not at the meeting. So I think that’s a pretty good measure of the size change we can make.

As far as new stuff…. we’ll probably come up with some terminology for talking about graphs, and maybe even a syntax which allows people to express information about graphs and subgraphs. But one could easily view that as just properly providing the functionality that RDF reification was supposed to provide. So, again, it’s just a (rather complicated) bug fix. And yes, making Turtle a REC, but it’s already a de facto standard, so (again) not a big deal.

The group also decided , with a bit of disappointment for some, not to actively push for a JSON serialization that appeals to non-RDF-folks. This was something I was interested in (cf JRON) but I agree there’s too much design work to do in a Working Group like this. The door was left open for the group to take it up again, if the right proposal appears.

So, it’s all good. I’m comfortable with all the decisions the group made in the past two days, and I’m really happy to be working with such a great bunch of people. I also had a nice time visiting Amsterdam and taking long walks along the canals. But, one of these days, I want my jet pack.

A few days ago IPTC published a press release on rNews: “ Standard draft for embedding metadata in online news ”. This is, potentially, a huge thing for Linked Data and the Semantic Web. Without going into too much technical details (no reason to repeat what is on the IPTC pages on rNews , you can look it up there) what this means is that, potentially, all major online news services on the globe, from the Associated Press to the AFP , or from the New York Times to the Süddeutsche Zeitung, will have have their news items enriched with metadata, and this metadata will be expressed in RDFa. In other words, the news items will be usable, by extracting RDF, as part of any Semantic Web applications, can be mashed up with other types of data easily, etc. In short, news item will become a major part of the Semantic Web landscape with the extra specificity to be an extremely dynamic set of data that is renewed every day. That is exciting!

Of course, it will take some time to get there, but we should realize that IPTC is the major standard setting body in the news publishing world. I.e., rNews has a major chance to be largely adopted. It is time for the Semantic Web community to pay attention…

Filed under: Semantic Web , Work Related Tagged: Linked Data , RDF , RDFa

Syarif Achmad has published a Indonesian translations of the OWL 2 Overview document, under the title “ Bahasa Ontologi Web OWL 2 - Dokumen Ikhtisar”.

The “SPARQL Inferencing Notation (SPIN)”specification has been published as a W3C Member Submission, co-authored by experts from TopQuandrant, Open Link Software, and the Rensselaer Polytechnic Institute. Based on RDF, RDF Schema and SPARQL, SPIN implements a rule and constraints language. SPIN uses an RDF based syntax for SPARQL that makes it possible to share SPARQL queries and update operations together with other RDF resources. Generic SPARQL engines can be used to execute those rules and constraints. SPIN also provides a vocabulary to describe executable SPARQL functions that can be used to extend the range of available functions to a SPARQL processor in a platform independent way.