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Re: DRAFT response to comment #54, Jan Wielemaker

From: Ivan Herman <ivan@w3.org>
Date: Sun, 15 Feb 2009 10:17:49 +0100
Message-ID: <4997DDBD.60707@w3.org>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: public-owl-wg@w3.org
Peter,

- I have no problem waiting to send out the reply to Jan until the
multi-syntax format issue is discussed and, hopefully, decided. That
should (I hope) happen at the f2f in cca. a week from now, so there is
no rush. You are right that it is better to rely on such decisions in
the reply.

- As for you more general comment... Jan's comment is not described in
very clear manner (to me), but I do not believe that getting into the
type of discussion you mention below is worthwhile or indeed appropriate
at this time. Jan is worried about his current toolchain, and the reply
I proposed also says:

[[[
... Ie, the situation has _not_ changed compared to OWL 1.
]]]

ie, his worries are unfunded. If he could live with OWL 1 then he could
live easily with OWL 2. That is the essence of what we have to say, the
rest is cherry on the cake, in fact... Let us not worry whether he will
have to change his toolchain later (eg, for RIF); this is not the
subject for a LC comment response in my view...

Cheers

Ivan

P.S. Jan's systems, based on Prolog, is primarily targeted at OWL Full
applications, so I believe his worries is really based on the false
assumptions that _another_, non triple based syntax is to be used.


Peter F. Patel-Schneider wrote:
> On further reflection, I do not at this time support a response that
> even alludes to putting multi-syntax formats into Syntax, at least
> without some *very* strong caveats. 
> 
> As well, Jan does not appear to be confused in the way you mention.  He
> is entirely correct that OWL2 provides a direct semantics for a non-RDF
> syntax.  This has always been the case since the beginnings of OWL.
> (The precursors of OWL didn't even have an RDF-compatible semantics
> (partly because there was then no RDF semantics).)  The only change in
> OWL 2 is that there is now a native XML syntax that is rec-track, as
> opposed to a note.
> 
> Jan is confused in other ways, including in his view of the Semantic Web
> as being only and always based on triples.  In fact, the standard view
> of triple-meaning is insufficient to support the as-yet-unimplemented
> levels of the Semantic Web stack.  Jan's toolchain will have to be
> fundamentally changed at some point in the future.  The history of OWL
> is to a large extent dominated by the attempt to keep Jan's toolchain as
> intact as possible while still admitting effective ontology reasoning
> for those who care.  If this message is not getting through, then
> perhaps it is not worthwhile to continue the effort.
> 
> All this said, I do not know how we should reply to Jan.  Acquainting
> him with the stark facts of representation and logical paradox may not
> be effective.  Maybe we could say that the two mappings 
> 	Functional Syntax -> Direct Semantics -> Inferences
> and
> 	Functional Syntax -> RDF -> RDF-Based Semantics -> Inferences
> commute as much as possible while retaining effective ontological
> reasoning, but, again, I am not sure that this is going to be
> effective. 
> 
> Peter F. Patel-Schneider
> Bell Labs Research
> 
> 
> From: Ivan Herman <ivan@w3.org>
> Subject: DRAFT response to comment #54, Jan Wielemaker
> Date: Wed, 11 Feb 2009 11:38:55 +0100
> 
>> This response is, actually, a possible pattern for a number of other
>> comments on the exact role of OWL/XML. Ie, if this is fine for the
>> group, we may want to reuse, essentially, the same text for a number of
>> others (to be exactly identified).
>>
>> The reason I chose this one is because Jan did _not_ question the rec
>> track aspect of OWL/XML per se (in contrast to, eg, the corresponding
>> UvA comment). In this sense this one is simpler...
>>
>> Here is the proposed text. I have also updated
>> http://www.w3.org/2007/OWL/wiki/LC_Responses/JR8.
>>
>> Ivan
>>
>> ========
>>
>> Dear Jan,
>>
>> Thank you for your comment
>>
>> <http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0069.html>
>> on the OWL 2 Web Ontology Language last call drafts.
>>
>> Unfortunately, your comment is based on a confusion, which is our fault
>> in not conveying the message clearly enough. The technical fact is that
>> there is no change between OWL 1 and OWL 2 in terms of the stack you
>> refer to in your comment.
>>
>> Indeed, Section 2.1 of the Conformance and Test Cases document states
>> the following:
>>
>> "Several syntaxes have been defined for OWL 2 ontology documents, some
>> or all of which could be used by OWL 2 tools for exchanging documents.
>> However, 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, if possible, be able to publish them in the RDF/XML
>> serialization if asked to do so (e.g., via HTTP content negotiation)."
>>
>> See:
>>
>> http://www.w3.org/TR/2008/WD-owl2-test-20081202/#Conformance_.28Normative.29
>>
>> In other words, the only _required_ exchange syntax among OWL 2 tools is
>> based on RDF and is RDF/XML (the only small caveat, referred to by the
>> 'if possible' remark in the text, is that there are valid RDF graphs
>> that cannot be serialized into RDF/XML, eg, if complex URI-s are used
>> for property IDs). Ie, the situation has _not_ changed compared to OWL 1.
>>
>> The confusion obviously comes from the fact that the OWL/XML syntax,
>> which was published as a note[1] for OWL 1, is now on Recommendation
>> track. OWL/XML for OWL 1 was an optional feature that OWL 1 tools could
>> implement if they wished to do so. The fact that OWL/XML is now planned
>> as a recommendation has not changed this.
>>
>> All that being said, the Working Group recognizes that this issue may
>> lead to confusion, as witnessed by a number of comments that expressed
>> the same concerns as yours. The group will take appropriate steps in
>> conveying this information better by, eg, including multi-syntax formats
>> into the functional specification, or making the situation clearer in
>> the appropriate status sections. Details of these steps are not yet
>> decided at this time.
>>
>> [1] http://www.w3.org/TR/owl-xmlsyntax/
>>
>> 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,
>> Ivan Herman
>> on behalf of the W3C OWL Working Group
>>
>> ===========
>> -- 
>>
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>> FOAF: http://www.ivan-herman.net/foaf.rdf

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf


Received on Sunday, 15 February 2009 09:18:20 GMT

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