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RE: Summary of strings, markup, and language tagging in RDF (resend)

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Thu, 3 Jul 2003 19:56:36 +0200
To: "Martin Duerst" <duerst@w3.org>, "Jeremy Carroll" <jjc@hplb.hpl.hp.com>, "pat hayes" <phayes@ihmc.us>
Cc: <w3c-rdfcore-wg@w3.org>, "Brian_McBride" <bwm@hplb.hpl.hp.com>
Message-ID: <BHEGLCKMOHGLGNOKPGHDAEMPCBAA.jjc@hpl.hp.com>

>
> >The key question is what will this achieve in terms of actual deployment.
> >What I have seen in webont is that at least some of the target community
> >for RDF is resistant to XMLliterals at all.
> >Every obstacle to easy deployment of XMLLiteral will be a reason to not
> >deploy it.
>
> So do you think that half-way deployment (in the sense that an
> unsatisfactory solution is deployed) is better?
>
> Just some background on why this argument which may look very
> convincing to you may not really help you to convince us:
>
> Traditionally, i18n people are not very sympathetic
> to arguments such as "this will be doing the right thing for 80%
> of the world, so let's do this rather than risk that things won't
> be done at all". For i18n, 80% is just simply not enough.
> Also, we are somewhat used to the unfortunate fact that i18n
> features don't always get implemented first. We just had to
> learn to live with it.

I am certainly not saying that.


>
>
> >Currently (based on the LC design) webont have declared that OWL tools
> >should minimally support xsd:string and xsd:integer, whereas
> >rdf:XMLLiteral is optional. This means that certain entailments are
> >implementation dependent
> >(contrast
> >http://www.w3.org/TR/owl-test/proposed-misc-200-xmlliteral#miscel
laneous-204
>http://www.w3.org/TR/owl-test/proposed-misc-200-xmlliteral#miscellaneous-20
5
>)
>The same file is constistent or inconsistent depending on implementation
>specific parameters (reasoning support for rdf:XMLLiteral, which is
optional).

>If I understand this example correctly, an OWL parser that does not
>support XML Literals will not be able to decide whether by chance,
><b>Good!</b> and <b>Bad!</b> might are actually the same after
>canonicalization, and therefore may not see that there is a conflict
>because there are two different property values for a functional
>property?

Well yes and no. Yes in that in the LC design canonicalization was done in
the reasoner. No, in that with our current design it is much easier for an
OWL reasoner to support rdf;XMLLiteral. The parser does the
canonicalization.

> If that's true, then there will be similar problems for datatypes
> such as float and double, and so on. Is that considered acceptable?

Yes

> If that's true, then it also means that the RDF parser actually
> does not do any canonicalization on the XML, nor that any RDF store
> would seem inclined to do canonicalization on the XML. That seems
> to me to be highly inefficient, i.e. in terms of actual implementations,

Yes we've changed it, the reagle-01, reagle-02 LC issues. This change is
essentially orthogonal to the xml:lang issue.

> If RDF parsers and RDF stores actually cannonicalize XML, then
> the question is why would it be so difficult for OWL applications
> to support it?

Ask WebOnt (there is no good reply in my view)

> Turned the other way round, when DanC asked us
> whether we are okay that only string and integer types have
> to be supported by OWL applications, we should probably have
> asked to add XML Literals, because the benefit for i18n is
> large while it seems that the actual cost on the OWL level
> is actually rather low.

too right


>> From my point of view this is a failure of *this* WG to have a design
>> that is sufficiently simple that implementors and others feel they can
>> commit to it. I believe that the simplifications we have made will be
>> beneficial for I18N, in that the only remaining difficulties for
>> XMLLiteral are in the parser, and many parser writers seem bought in to
>> doing the work.
>
>So do they actually do the canonicalization, or not?

Some do, we believe the others will.

Jeremy
Received on Thursday, 3 July 2003 13:56:52 EDT

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