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Proposed response to Dave Reynolds on dataranges

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Sun, 27 Jul 2003 12:49:37 +0100
Message-ID: <16163.48209.738746.619939@merlin.horrocks.net>
To: Jim Hendler <hendler@cs.umd.edu>
Cc: www-webont-wg@w3.org

Here is a proposed response to Dave Beckett on his named datarange
comment.

Ian

=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+

Dave,

Thank you for your comments.

I will attempt to provide some further clarification regarding the
WG's decision not to support naming of data ranges. The second part of
your comment (regarding bNodes) is/will be dealt with separately.

The issue of named dataranges was discussed at the editors meeting in
Boston. (see [1]). The following potential problems were identified:

1. Clearly, we would like to have access in OWL to a full range of
user-defined XML Schema datatypes derived from the built-in datatypes
that can already be used in OWL (see [2]). This would include
enumerated datatypes corresponding to OWL dataranges. We expect
XML:Schema to ultimately provide a mechanism to support this. Naming
dataranges in OWL would provide a "completing" mechanism (i.e.,
provide an alternative way to name user defined datatypes), and this
could interact in an undesirable way with the XML:Schema mechanism as
and when it is introduced.

2. OWL DL is designed so as to allow reasoning about datatypes and
values to be cleanly separated from reasoning about classes and
individuals. Introducing OWL names for dataranges may compromise this
design.

It was therefore decided not to include them in the language at
present. It may be possible to add them in the future as and when a
thorough investigation of the issues proves that they would not have
any adverse effects.


Please reply to this message as to whether this response is satisfactory,
copying public-webont-wg@w3.org. Again, thank you for your comments.

Ian Horrocks


[1] http://lists.w3.org/Archives/Public/www-webont-wg/2003Mar/0038.html
[2] http://www-db.research.bell-labs.com/user/pfps/owl/semantics/semantics-all.html#2.1


> Message-ID: <3F1E5386.A80B1974@hplb.hpl.hp.com>
> Date: Wed, 23 Jul 2003 10:21:10 +0100
> From: Dave Reynolds <der@hplb.hpl.hp.com>
> To: Jim Hendler <hendler@cs.umd.edu>
> CC: public-webont-comments@w3.org
> Subject: Re: OWL comment - blank nodes in OWL DL
> 
> 
> Jim,
> 
> Thank you for your response to the Jena team comments on these issues.
> Overall this response is not (yet) acceptable. 
> 
> (a) Issue: Named data ranges
>      Your response: postpone
> 
> We understand that the working group cannot name user-defined XSD datatypes 
> and that matter should be raised with the XML Schema working group.
> 
> Our concern was more one of uniformity - it seems possible to have both 
> named and unnamed classes, why not data ranges? The more uniform a language 
> is, the easier the API and the fewer the support calls.
> 
> As an example could this:
> 
> <owl:DataRange rdf:about="#MyDR">
>     <owl:oneOf>
>        <rdf:List>
>          <rdf:first>foo</rdf:first>
>          <rdf:rest rdf:resource="&rdf;nil"/>
>        </rdf:List>
>     </owl:oneOf>
> </owl:DataRange>
> 
> be included in OWL DL, for greater uniformity with other unnamed things in 
> OWL DL (which can optionally be named).
> 
> I confess to not understanding the research problems that you refer to as 
> being raised by naming data ranges. If there is some non-trivial problem 
> here then we certainly accept this is not a sufficiently important issue to 
> warrant additional research at this stage in the process.
> 
> Has the WG discussed this question?
> None of the three links you gave seemed directly related to our request:
> [1]
> http://www.w3.org/2001/sw/WebOnt/webont-issues.html#I5.8-Datatypes
> [2]
> http://www.w3.org/2001/sw/WebOnt/webont-issues.html#I4.3-Structured-Datatypes
> [3]
> http://lists.w3.org/Archives/Public/www-webont-wg/2002May/0040.html
Received on Sunday, 27 July 2003 07:50:50 GMT

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