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Re: (Round 2) Proposed Extensions to OWL

From: Roger L. Costello <costello@mitre.org>
Date: Mon, 07 Jul 2003 06:55:10 -0400
Message-ID: <3F09518E.6AC3FE87@mitre.org>
To: www-rdf-interest@w3.org
CC: "Costello,Roger L." <costello@mitre.org>, jon@spin.ie

"Richard H. McCullough" wrote:
> 
> This conceptual model is OK, but unnecessarily complicated,
> and produces RDF descriptions which are just too long.
> 
> Since these physical quantities are just literal numbers,
> they can be expressed as attributes of attributes, e.g.
>     <ex:River ex:Yangtze>
>         <ex:length units:kilometer=6300/>
>     </ex:River>

Hi Richard,

Jon Hanna addressed this very nicely last Thursday.  He wrote:

This has advantages of brevity. However we can't deal as well with:

<River rdf:ID="Yangtze">
    <length>
        <Length len:lengthInMiles="3914"/>
    </length>
    <length>
        <Length len:lengthInMiles="3900"/>
    </length>
</River>

(Which might occur if we had two sources for lengthInMiles with
different degrees of precision).

We could deal with:

<River rdf:ID="Yangtze">
  <length>
    <Length>
      <measurement>
        <LengthInMiles number="3914">
      </measurement>
      <measurement>
        <LengthInMiles number="3900">
      </measurement>
    </Length>
  </length>
</River>

Because the two measurements are (at least possibly) distinct despite
their being only one length with only one Length. This also gives us
somewhere to put information about the degree of precision, whether the
application producing the value is authorised and/or tested by some
organisation (say NIST, NWML, LMS etc.) and so on.

The greater notational and processing burden is appropriate for
something that intends to cope with a large range of needs for
measurements and conversions. A more abbreviated version like
len:lengthInMiles would be more appropriate much of the time, allowing
support for both styles would be ideal.
Received on Monday, 7 July 2003 06:57:06 GMT

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