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(offlist) Re: Datatyping Summary

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Wed, 30 Jan 2002 09:12:33 +0200
To: ext Graham Klyne <Graham.Klyne@MIMEsweeper.com>
CC: Jeremy Carroll <jjc@hplb.hpl.hp.com>, Brian McBride <bwm@hplb.hpl.hp.com>, <www-archive@w3.org>
Message-ID: <B87D6981.CA0B%patrick.stickler@nokia.com>

[offlist]


On 2002-01-29 22:18, "ext Graham Klyne" <Graham.Klyne@MIMEsweeper.com>
wrote:

> At 09:02 PM 1/29/02 +0200, Patrick Stickler wrote:
>> The only show stopper that has been claimed for TDL is
>> that it doesn't have tidy literals -- based on the view
>> that e.g. "1984" always means the same thing. I hope that
>> it has become clear that this view is not
>> valid in an environment of global interchange between
>> disparate sources of knowledge.
>> 
>> So it should be concluded that there are no show stoppers
>> for TDL.
> 
> I find this completely non sequitur.
> 
> If any show stopper can be removed by introduction of a different show
> stopper, that doesn't mean there are no show stoppers.

I'm not sure I follow you there. Both Dan and Sergey in their "can't
live with S" postings focused primarily on the fact that because TDL
presumed untidy literal nodes, it was fundamentally broken. I.e.

--

Dan: http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Jan/0289.html

TDL[TDL] does not meet the "duh!" requirement.
(the TDL proponents will please correct
me if I have misunderstood, but I'm pretty
sure, based on the clarification of TDL
I just got in the telcon, that it does not.)
Therefore I find it totally unacceptable.

--

Sergey: http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Jan/0293.html

A major problem with TDL [1] is that it requires RDF graphs to be untidy
on literals. This requirement would breaks most RDF applications that I
am aware of.
...
Existing applications that assume RDF graphs to be tidy on literals can
safely conclude that the two literals in the above graph are identical.

--

Responses from Jeremy, myself, and Pat have, I believe, made
it clear that untidyness is required somewhere, and that where TDL
chooses to deal with that untidyness is both valid, correct, and
not broken. Applications which presume global consistency of meaning
for literals are closed systems and not following the "spirit"
of RDF as a means of global interchange of context independent
knowledge.

I am not introducing any other show stopper (which specifically
did you mean) but pointing out that the presumed show stopper for
TDL based on untidy literals was not in fact any show stopper.

If TDL appears to "break" applications that presume global
meaning for literals regardless of context, then it is in fact
those applications which are defective and not TDL.

TDL is doing those applications a favor by showing that they
are making system-specific, closed context presumptions about
the datatyping interpretation of literals, interpretations which
rather should be based on knowledge expressed in the RDF and
thus consistent globally for all applications.
 
Thus TDL is not broken as Dan and Sergey claim.

> I am still open to a TDL proposal that actually works.  From a stylistic
> viewpoint, I can agree that it is neater.

I'm glad to hear that, and I can also say that I am not completely
closed to S if the issues of compatability of local and global
idioms and no recourse to idiom specific vocabularies can be
addressed (because, even if you don't see that as a problem, it
is a show stopper to me). Though that doesn't mean that I don't
still have concerns about the impact S will have on further
adoption and use of RDF by "common folk".

I have a few specific questions, in the aim of understanding
your prior and remaining concerns about TDL, particularly with
regards to entailment:

Given the fact that untidy literals for TDL are both neccessary
and valid (i.e. the "Duh!" test is flawed) do your concerns
about entailment remain? (for the original definition of TDL,
not the recent "manditory bnode" variant)

I.e. is it correct to expect that entailment be based on
the presumption that literals have consistent global meaning
independent of context?

How does TDL meet the entailment requirements if based on the
interpretation level, meaning, if per my example near the end of

http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Jan/0365.html

every literal was replaced by the TDL pairing(s) that actually
apply? 


Thanks,

Patrick

--
               
Patrick Stickler              Phone: +358 50 483 9453
Senior Research Scientist     Fax:   +358 7180 35409
Nokia Research Center         Email: patrick.stickler@nokia.com
Received on Wednesday, 30 January 2002 02:11:31 GMT

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