Re: Invitation for review of POWDER documents (Last Call)

Dear Phil,

thanks for your note. We have indeed found some problems in section 4.6
of http://www.w3.org/TR/2009/WD-powder-formal-20090403/ which needs
updates. They are as follows.

- The reference should be to XSD1.1 and not XSD2:
      http://www.w3.org/TR/xmlschema11-2/

- 'At the time of writing, the OWL-2' should say "OWL 2" (ie, no hyphen)

- The reference to OWL 2 currently points to the OWL 2 Primer. We think
it would be better if it pointed at the (new) OWL 2 Document Overview:
http://www.w3.org/TR/owl2-overview/

- The semantic condition refers to rdfs:Resource for the domain of
hasIRI. Although the description refers to an extension of the RDF
semantics, it makes use of, say, owl:DatatypeProperty. Hence it may be
stylistically better to refer to owl:Thing.

- The encoding of the condition in the example has several problems,
partially due to some recent changes in OWL 2. These are:

    - namespace changes (OWL 2 refers to xsd:pattern directly and not
owl:pattern (OWL 2 reuses rdfs:Datatype instead of owl:datarange)

    - we also think that the type of restriction used is inappropriate.
owl:hasValue should refer to a single individual and not to a
datatype/datarange. Based on the rest of the POWDER semantics, what you
probably have to use is owl:allValuesFrom, but this is something you
have to decide, of course

    - the RDF mapping of facets is based on a list of blank nodes
instead of the approach used in the current code

The first example (the second has similar structure) should look
something like:

<owl:Restriction>
  <owl:onProperty rdf:resource="....#hasIRI"/>
  <owl:allValuesFrom>
    <rdfs:Datatype>
      <owl:onDatatype rdf:resource="...#string"/>
      <owl:withRestrictions rdf:parseType="Collection">
        <rdf:Description>
          <xsd:pattern rdf:datatype="...#string">PATTERN</xsd:pattern>
        </rdf:Description>
      </owl:withRestrictions>
    <rdfs:Datatype>
  </owl:allValuesFrom>
</owl:Restriction>


We are sorry not to have spotted this issue earlier.

Sincerely

Ivan
(In the name of the OWL 2 Working Group)


Phil Archer wrote:
> Dear OWL and DAWG Team contacts and chairs,
> 
> You may well have seen the more formal announcement of this that I sent
> to the chairs list earlier (copied below). Bijan rightly pointed out
> that you should also be alerted to this.
> 
> Our Formal Semantics document
> (http://www.w3.org/TR/2009/WD-powder-formal-20090403/) has already
> received substantial review and is regarded (by us!) as stable. It does,
> however, make an informative reference to OWL 2 in section 4.6 which,
> AFIAK, hasn't elicited any comment. Section 5 also includes some
> (normative) SPARQL queries. Any comment on these sections would be
> particularly welcome from your groups.
> 
> Copy of original announcement below.
> 
> Thanks for your help.
> 
> Phil.
> 
> The POWDER Working Group has been developing a suite of documents that
> specify a protocol for publishing descriptions of Web resources. The
> documents have already had wide review and the group has running code.
> However, an internal team review of one document has prompted the
> working group to make a third Last Call announcement, highlighting one
> particular area.
> 
> * POWDER: Grouping of Resources
>   http://www.w3.org/TR/2009/WD-powder-grouping-20090403/
> 
> includes sections on IRI canonicalization (section 2.1.3 - 2.1.5) and it
> is this that we are keen to ensure is correct.
> 
> Two other Recommendations Track documents have undergone editorial
> changes since the previous Last Call (made in November 2008) and no
> substantive changes are expected to be made before the group seeks
> transition to Proposed Recommendation. They are:
> 
> * POWDER: Formal Semantics
>   http://www.w3.org/TR/2009/WD-powder-formal-20090403/
> 
> * POWDER: Description Resources
>   http://www.w3.org/TR/2009/WD-powder-dr-20090403/
> 
> The Working Group has also published two updated Working Drafts that are
> expected to become Working Group Notes:
> 
> * POWDER: Primer
>   http://www.w3.org/TR/2009/NOTE-powder-primer-20090403/
> 
> * POWDER: Test Suite
>   http://www.w3.org/TR/2009/NOTE-powder-test-20090403/
> 
> We welcome feedback on these publications through to Monday 27th April
> as well.
> 
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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