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FW: XML Schema vs DAML/RDF/RDFS

From: Margaret Green <mgreen@nextance.com>
Date: Wed, 17 Apr 2002 14:37:05 -0700
Message-ID: <458473676F1AC74A84EAB2F22004DA6D0BF60B@mail.nextance.com>
To: <www-rdf-interest@w3.org>
Sorry :->

-----Original Message-----
From: Charles McCathieNevile [mailto:charles@w3.org] 
Sent: Wednesday, April 17, 2002 2:34 PM
To: Margaret Green
Subject: RE: XML Schema vs DAML/RDF/RDFS

Did you mean to send this to the list? If so, please feel forward to
send
with my reply too ;-)

conjecture: Right, me too.

I think the situation Guha has is that the knowledge they are using has
been
modelled successfully already (I agree that is a hard part, and one
value of
an RDF-based system).

The power of being able to generate assertions that lead to new
assertions
isn't restricted to RDF - the same things are modelled in
special-purpose XML
schemas. But again it is the general applicability that RDF adds as
value...

I think...

cheers

Charles

On Wed, 17 Apr 2002, Margaret Green wrote:

  First remember I am only involved in conjecture.

  Intuitions.
  1. New knowledge can't be modeled ahead of time, before it takes form.
  Without form I'm hard pressed to explicate a strong structure
definition
  in XML Schema.

  2. RDF Model Theory in 6.2 of RDFS-entailment and RDFS closures lists
a
  set of closures to be applied to generate "all legal RDF triples". I
can
  see that the addition of an analysis result triple could cause other
  triples to be generated that would be new connections to other
analyses.

  Margaret Green

  -----Original Message-----
  From: Charles McCathieNevile [mailto:charles@w3.org]
  Sent: Wednesday, April 17, 2002 2:01 PM
  To: Margaret Green
  Cc: R.V.Guha; www-rdf-interest@w3.org
  Subject: RE: XML Schema vs DAML/RDF/RDFS

  Are these inferences that cannot be built on using XML and schema for
  everything, and then processing with XML queries?

  It seems to me that often most of the use cases can be satisfied that
  way,
  but that there are some interesting ones which can't. In working on
the
  EARL
  specification we are now considering requiring that conformant
  applications
  can produce a particular XML syntax (which would probably be a
  particular
  view of RDF/XML) as well as being able to handle real RDF. The idea is
  that
  there are some things which are really RDF problems - extending the
  types of
  results from "fail" to "nearly passes", "passes except for X", "fails
  except
  for Y" or "completely fails" is easy in RDF, where the result can be
  held,
  and processed if it is understood, or processed just as a type of
  "fails". On
  the other hand there are a lot of applications that can be
accomplished
  by
  simple XML approaches - put everything in a rigid tree, so I can
  optimise
  searching for content that passes some set of requirements.

  It seems to me that it is fairly easy to convert an XML schema into
  RDF+etc,
  but not easy to do the other way around. Is it useful to ask "why
should
  RDF
  applications not have an XML Schema"?

  chaals

  On Wed, 17 Apr 2002, Margaret Green wrote:

    Their analyses produce results. These results are assertions. I
would
    model the analytical results. There may be the potential for
  inferences
    to be drawn among sets of results - a form of meta-analysis, if you
    will.


    Margaret Green


    -----Original Message-----
    From: R.V.Guha [mailto:guha@guha.com]
    Sent: Wednesday, April 17, 2002 1:24 PM
    To: www-rdf-interest@w3.org
    Subject: XML Schema vs DAML/RDF/RDFS


    I was talking yesterday to a friend whose is working with
    some geologists who want to share data. They are of
    course planning on using xml and are in the process
    of writing up their xml schemas.

    They have applications that do all kinds of sophisticated analysis
    on this data. They have no need of doing the kinds of inferences
    that rdfs/daml enables. Their apps do computations that are far
    more complex and it would be easy for them to modify their
    apps to make it do the few (if any) inferential facilities rdfs/daml
    offers, if the need arises.

    I tried to make a case for  rdf/rdfs/daml, but given the
    substantially more tools available for xml/xml schema and their
    lack of interest in simple inferences, I couldn't in good faith push
    too hard for rdf/rdfs/daml.

    So, should they be using rdfs/daml? Why?

    guha




-- 
Charles McCathieNevile    http://www.w3.org/People/Charles  phone: +61
409 134 136
W3C Web Accessibility Initiative     http://www.w3.org/WAI  fax: +33 4
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Received on Wednesday, 17 April 2002 17:37:59 GMT

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