Proposed Consensus Review of RDF Core Documents

Guus and I have worked (with advice from Dan) to boil down our 
reviews of the RDF documents into a single proposed consensus review. 
We  will discuss on the telecon today (Feb 20).   We will ask Herman, 
Raphael and Jean-Francois to post their individual reviews directly 
to www-rdf-comments@w3.org, with this summary being our consensus 
comments.



================
RDFCore LC documents
Response by the Web Ontology Working Group (draft)
21 Feb 2003

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RDF Design Issues
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i. Design of rdf:XMLLiteral and rdf:parseType="Literal":

The full integration of this feature of RDF into OWL necessitates that the
denotation in the domain of discourse be fully defined by the source RDF/XML
file. We therefore request that you remove sufficient implementation 
variability to ensure that this is the case.  An example fix would be 
to require an RDF/XML parser to use a specific canonicalization on 
input.

We have resolved that rdf:XMLLiteral will be a built-in datatype in 
OWL Lite, OWL DL and OWL Full contingent on a satisfactory response 
from RDF Core WG on this comment.

ii.Constraints on rdf:parsetype="Collection"

We would prefer that rdf:parsetype="Collection" would be allowed to 
be a list of literals, not just a list of RDF node elements.  This, 
would permit some constructs in OWL that are difficult under the 
current design.

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Consensus comments on the RDF Concepts Document
--------------------------------------------

We believe the RDF Concepts Document is a useful document and helpful 
in understanding RDF and its use.  However, out Working Group did 
have some concerns with respect to the issue of social meaning as 
discussed in this document.

The Web Ontology WG has mixed views on this issue and could not agree 
on a specific consensus response in the time available.  However, we 
note that a number of participants in the Webont WG have reservations 
about the RDF view on the social meaning of RDF. For example, it was 
felt by some to be unacceptable that two classes that differ only in 
their rdfs:comment content would not entail each other.

We did reach consensus to request that the wording in the RDF Schema 
and the RDF Concepts documents be rephrased to explain this issue, 
and particularly its impact, more clearly, as this has ramifications 
on other languages, such as OWL, which are extensions to RDF.

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Consensus comments on the RDF Schema Document
--------------------------------------------
We believe that the design of the language, as reflected in the LC 
documents, is such that OWL can appropriately use RDF Schema and 
endorse this design.

Raphael Volz of our group has prepared a detailed review of this 
document which he will send to the RDF Core WG.  The Web Ontology 
Working Group agrees with the spirit of his review and summarizes our 
comments below:

i. Although this document is called RDF Schema we think that the 
title "RDF Vocabulary Description Language" would be clearer, and 
make the difference from XML Schema (used for validation) more 
evident.

ii. The current design does not specify what the behavior is for 
domain/range constraints stated on super-properties wrt. to 
subproperties.  We would request that a default behavior be specified.


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Consensus comments on the RDF Semantics document
--------------------------------------------
We believe that the design of the semantics, as reflected in the LC 
documents, is such that OWL will be able to layer appropriately. 
However, we have a number of concerns that need to be addressed to 
improve the document (and, in particular, to fix some inconsistencies 
in the current document).

Herman ter Horst of our group has prepared a detailed review of this 
document itemizing inconsistencies he has found.  The Web Ontology WG 
endorses the spirit of his review, and has asked Herman to help 
insure that the final RDF Semantics document is edited to fix the 
inconsistencies and editorial issues that he identifies.
-- 
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  240-731-3822 (Cell)
http://www.cs.umd.edu/users/hendler

Received on Thursday, 20 February 2003 06:20:11 UTC