POWDER update

The POWDER Working Group has had three key meetings in the last 9 days.

A quick reminder – POWDER is designing a lightweight system that will enable RDF triples to be applied to groups of resources, typically all those available from a given Web site. Critically, the data will be open to authentication so that when Organization A says that Web site B has properties C, D and E, a machine will be able to seek authentication from Organization A that they really did say that. Think of it as the automated/Semantic Web version of ‘Click to Verify’ when you see a trustmark on a Web site.

On the first of these meetings we also agreed on a coordination step with the Web Application Formats Working Group relating to their Enabling Read Access document. We also made significant progress towards defining the details of the structure of a Description Resource (a more detailed summary of this meeting is also available).

We also had a public event, jointly sponsored by CTIA. This “Stakeholder Meeting” presented several use cases and discussed the potential—and potential problems—of the new protocol. A full report is available.

Finally, a meeting was held with the Mobile Web Best Practices Working Group to discuss mobileOK. This is a key use case for POWDER as it encodes a claim that a group of resources are conformant with Mobile Web Best Practice.

As a result of all these meetings, it’s possible to present a sample Description Resource. One or two minor details have yet to be finalized but this is a good snapshot.

1  <wdr:DR>
2    <foaf:hasMaker rdf:resource="http://www.example.com/foaf.rdf#me" />
3    <dcterms:issued>2007-07-17</dcterms:issued>
4    <wdr:validFrom>2007-07-21</wdr:validFrom>
5    <wdr:validUntil>2008-05-21</wdr:validUntil>
6    <wdr:hasScope>
7      <wdr:ResourceSet>
8        <wdr:includeHosts>example.org</wdr:includeHosts>
9      </wdr:ResourceSet>
10    </wdr:hasScope>
11    <wdr:hasDescriptors rdf:resource="http://www.w3.org/2007/07/mobileOK#Basic" />
12    <dc:description>example.org conforms to the mobileOK Basic standard, meaning that basic steps have been taken to provide a functional user experience for users of basic mobile devices</dc:description>
13    <foaf:depiction rdf:resource="http://www.w3.org/ICONS/mobileOKPro.png" />
14  </wdr:DR>

The namespace declarations are omitted for clarity but wdr is an abbreviation represents the POWDER namespace (it’s an abbreviation of Web Description Resources).

Some elements are mandatory:

  • Attribution (foaf:maker)
  • Scope (wdr:hasScope and the Resource Set it points to)
  • The actual descriptors that can be applied to any Resource that matches the Resource Set definition (wdr:hasDescriptors which has a range of a Class called ‘Descriptors’)

All other elements are optional, however, an issue date and a valid until date SHOULD be there.

The most tricky and contentious aspect of all this is likely to be the Resource Set definition. As noted in a blog last week, the relevant document is now a first public working draft. The ambitious target is to get a working draft of the Description Resources document into the public domain around the end of the month.

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