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Re: Comment on RDF Schema 1.0 dated 12 Nov. 2002

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Fri, 06 Dec 2002 14:32:06 +0000
Message-Id: <5.1.0.14.0.20021206142603.02820b40@0-mail-1.hpl.hp.com>
To: MDaconta@aol.com, www-rdf-comments@w3.org

Michael,

Thank you for these comments.  I'm sorry about the long delay in responding.

At 18:16 17/11/2002 -0500, MDaconta@aol.com wrote:
>Hi RDF WG,
>
>In reviewing the RDF Schema specification I believe the
>property rdfs:isDefinedBy is ambiguous as currently specified.
>The document presents four facts about the property:
>
>1. it is a resource that defines the subject.  However, how it defines
>the subject is never specified.  Additionally, the domain and range
>are both rdfs:Resource which offers no indication of how this defines
>the resource.

That is true.  The property places no constraints on how the resource 
defines the property.


>2. the document overview describes it as the namespace of the resource.
>Which is something that would presumably be handled by the namespace
>prefix and namespace declaration - therefore possibly making this
>property redundant.

That is an error.  It is not necessarily the namespace of the 
resource.  However, even if it were, it would not be redundant as the 
namespace prefix is not part of the RDF abstract syntax - its just an 
artifact of the xml encoding.


>3. In appendix B, the property is used and the value is the namespace;
>however, the URI retrieves the RDF Schema with the definitions.  It would
>be useful if this practice was documented and specified by the rdfs:Range
>of this property.

The WG decided that the value of the property is not constrained to be an 
rdf schema.  It can be, but is not required to be.


>4. the property is stated to be a subPropertyOf rdfs:seeAlso. To me, this
>is the most confusing aspect as the common use of seeAlso is optional;
>whereas, identifying a defining resource is usually mandatory (as in
>the definition of a "valid" XML document).

There is no requirement in RDF on any resource that it have an isDefinedBy 
property.  Its not mandatory.


>It would be beneficial for this property to be more concretely defined as
>well as addressed in the Primer.

Thank you for the feedback Michael.

Brian
Received on Friday, 6 December 2002 09:30:41 GMT

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