W3C home > Mailing lists > Public > www-rdf-interest@w3.org > November 1999

Re: A simple question....

From: Stefan Decker <stefan@DB.Stanford.EDU>
Date: Wed, 17 Nov 1999 02:21:20 -0800
Message-Id: <4.2.0.58.19991117022017.00c86af0@db.stanford.edu>
To: www-rdf-interest@w3.org
At 04:56 PM 11/17/99 +0800, you wrote:
>This issue appears quite often.
>For example, in the "Simpler Syntax" document that Tim Berners-Lee
>posted ( http://www.w3.org/DesignIssues/Syntax ) he included a section
>discussing this "Identifiers - what is identified?".
>Is it that, in contrast to C, etc, XML appears to be missing a syntax element
>to indicate to a user agent that the identifier should be dereferenced?

It seems so, yes.
There should be a defined way of dereferencing resources.
There are two ways of realizing this:
1) One could not put this in the RDF-model and define the model in such a 
way, that
    everything is as much dereferenced as possible.
    Then the parser, which genererates the tripel, has to do the work.

2) The other way is to extend the RDF-model in such a way, that it is 
possible to
    indicate, that a particular URI should be dereferenced.
    By this the application can decide, if it is necessary to dereference it.

I vote for 2) because otherwise parsing can be a time-consuming thing
(each dereferencing means downloading a new resource from the web)
And the application better knows, if it is really necessary to dereference 
the URI
(and can be done when needed)


There is actually a third way:
         Generating a new extra triple, that indicates that the resource 
should be
        dereferenced. But this involves reifying the original one and thus
        generates much more additional triple, and an application has a 
hard job to do.
         However, this would not change the data model. But it has to be 
standardized.

BTW:
Having links is a fundamental issue on the web - and there should be facilities
inside RDF to handle links.

I'am i missing anything?

Ciao,
         Stefan



>Stefan Decker wrote:
> >
> > Hi,
> >
> > a question and maybe an RDF 2.0 requirement ;-)
> >
> > Lets say, i have the following HTML-code in my homepage
> > (e.g. http://www.aifb.uni-karlsruhe.de/~sde ;-)
> >
> > ...
> > <center><A name="myname">Stefan Decker</A></center>
> > ...
> >
> > In which respect are the following RDF-snippets identical?
> >
> > 1)
> >
> >    <rdf:Description about="http://www.aifb.uni-karlsruhe.de/~sde">
> >        <s:Creator>Stefan Decker</s:Creator>
> >      </rdf:Description>
> >    </rdf:RDF>
> >
> > 2)
> >    <rdf:Description about="http://www.aifb.uni-karlsruhe.de/~sde">
> >        <s:Creator resource="http://www.aifb.uni-karlsruhe.de/~sde#myname"/>
> >      </rdf:Description>
> >    </rdf:RDF>
> >
> > I know that they will produce different triples, but is there a way
> > to guarantee, that an application behaves the same, regardless what it
> > will get?
> >
> > Background:
> > We have created an extended WYSIWYG-HTML-Editor, which allows to semantic
> > annotation of text. One simply marks the text and selects the
> > class/attribute from an ontology. Semantic Markup is inserted into
> > the HTML-text.
> > However, the editor now supports the ontobroker-annotation language,
> > but i would like to switch this to RDF (we worked on that concept
> > before RDF was born...)
> >
> > On the other side, i don't want to COPY the marked text from of the 
> HTML-page,
> > but would like to POINT to it. Otherwise if the HTML-page changes the
> > metadata will be invalidated, and thats something i would like to
> > avoid.
> >
> > Thanks,
> >
> >         Stefan
>
>--
>Best                    Simon
Received on Wednesday, 17 November 1999 05:23:50 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:42 GMT