[LC response] To SWD WG

Dear SWD WG,

Thank you for your comment
      <http://lists.w3.org/Archives/Public/public-owl-comments/ 
2009Feb/0012.html>
on the OWL 2 Web Ontology Language last call drafts.

OWL 2 is a successor of OWL and not only a successor of OWL DL. You  
are right, however, in pointing out that this is not made  
sufficiently clear in some documents, and that they sometimes seem to  
suggest that this is not the case.

In order to address this problem the WG has added a Document Overview  
and has revised several of the other documents. The Document Overview  
provides a high level view of the design, making it clear that OWL 2  
refers to the language as a whole, that an OWL 2 ontology can be  
equivalently seen as an RDF graph or as an abstract structure (an  
instance of the ontology class), and that ontologies can be  
interpreted using either the RDF-Based semantics or the Direct  
semantics (see our response to Frank van Harmelen [1] for more on  
this topic).

Regarding the presentation of the material, the Structural  
Specification and Functional-Style Syntax document, which is the core  
reference for language features and usage, has been revised so that  
the features are illustrated using examples in both functional and  
triple based syntaxes. The New Features and Rationale document is not  
intended as a language reference, but documents the rationale for the  
new features of OWL 2. In order to keep the document short only the  
more compact functional syntax is provided. This document is,  
however, not yet at last call, and so is still subject to change.

Regarding the RDF/XML exchange syntax being the normative exchange  
syntax, this is now more clearly emphasised. E.g., the new Document  
Overview [1] explicitly states that "The primary exchange syntax for  
OWL 2 is RDF/XML [RDF Syntax]; this is indeed the only syntax that  
must be supported by all OWL 2 tools (see Section 2.1 of the OWL 2  
Conformance document [OWL 2 Conformance])." The message is repeated  
elsewhere, e.g., in the Conformance and Test Cases document [2],  
where it says that "conformant OWL 2 tools that take ontology  
documents as input(s) MUST accept ontology documents using the RDF/ 
XML serialization [OWL 2 Mapping to RDF Graphs], and conformant OWL 2  
tools that publish ontology documents MUST be able to publish them in  
the RDF/XML serialization if asked to do so".

We are grateful for your supportive comments regarding some of the  
new features of OWL 2, and we hope that the changes we have made  
address your concerns about the presentation.

[1] http://www.w3.org/2007/OWL/wiki/Document_Overview
[2] http://www.w3.org/2007/OWL/wiki/Conformance_and_Test_Cases

Please acknowledge receipt of this email to <mailto:public-owl- 
comments@w3.org> (replying to this email should suffice). In your  
acknowledgment please let us know whether or not you are satisfied  
with the working group's response to your comment.

Regards,
Ian Horrocks
on behalf of the W3C OWL Working Group

Received on Thursday, 19 March 2009 17:38:54 UTC