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Re: Integrity Checking vs. Typing [Re: RDFS bug "A property canhave at most one range property"]

From: Wolfram Conen <conen@gmx.de>
Date: Sun, 18 Nov 2001 18:26:36 +0100
Message-ID: <3BF7EF4C.EC06AF2C@gmx.de>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: www-rdf-interest@w3.org

> If you are making any claims as to what the RDFS CR suggests, then I think
> that you have to consider the second paragraph of its section on
> constraints:
> 
>   RDF Schema provides a mechanism for describing such constraints, but does
>   not say whether or how an application must process the constraint
>   information.  For example, while an RDF schema can assert that an
>   <code>author</code> property is used to indicate resources that are
>   members of the class <code>Person</code>, it does not say whether or how
>   an application should act in processing that class information. We expect
>   that different applications will use these constraints in different ways
>   - e.g., a validator will look for errors, an interactive editor might
>   suggest legal values, and a reasoning application might infer the class
>   and then announce any inconsistencies.
> 
> There you have it---the ultimate cop-out.
> 
> From this, I don't see how anyone can claim that the RDFS CR comes down on
> the side of integrity constraints.

..or on any other side, for that matter. But there are numerous other
quotes possible that suggest it  - examples have been given earlier, see
for example this excerpt from Section 1:
    "This document does not specify a vocabulary of descriptive elements 
     such as "author". Instead, it specifies the mechanisms needed
     to define such elements, to define the classes of 
     resources they may be used with, to restrict possible 
     combinations of classes and relationships, and to 
     detect violations of those restrictions."
Can it more obvious? There are certainly both interpretations covered in
the RDFS CR (I remember someone calling it ambigous). The questions
remains: what interpretation is useful? And how to deal with schemata
that where made with the integrity constraint interpretation in mind?

Best,
	Wolfram
Received on Sunday, 18 November 2001 12:27:08 GMT

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