Re: common properties and rdfs:___domain

Matt, that sounds correct. But in your schema, if you need title, identifier etc. properties that may be slightly different, wouldn't inheriting from dc:title give you what you need?  You can decide the different domains etc. for these properties...

Revi


----- Original Message ----
From: "Johnson, Matthew C. (LNG-HBE)" <Matthew.C.Johnson@lexisnexis.com>
To: semantic-web@w3.org
Sent: Wednesday, June 11, 2008 11:29:01 AM
Subject: common properties and rdfs:___domain

 
Hi all,
 
When I originally read the RDFS spec some time ago, I
breezed over the concept of rdfs:___domain with the assuredness of an OO
programmer that that the concept mapped nicely to my own conception of a class
(silly me).  Reading �Semantic Web for the Working Ontologist�
[1] has caused me to do a few double takes in my reading (my neck hurts now). 
I�d like to see if my understanding is now correct.
 
mysch:p1 rdfs:___domain mysch:A .
myinst:me mysch:p1 �something� .
 
Would allow one to infer:
 
myinst:me rdf:type mysch:A .
 
without explicitly providing that triple.
 
Furthermore, an additional ___domain statement of:
 
mysch:p1 rdfs:___domain mysch:B .
 
would cause:
 
myinst:me rdf:type mysch:B .
 
to also be inferred.
 
Assuming this is good so far, is it safe to assume that one
should specify a class as a part of a property�s ___domain ONLY IF one is
prepared to say that all subjects that use that property are in ALL of the
classes specified by the ___domain regardless of whether that typing is explicitly
stated?
 
My use-case that started this is common/generic properties
such as Dublin Core�s �dc:title�, �dc:identifier�,
etc.  My original OO-inspired approach had me explicitly stating the ___domain
of these properties [within my schema] based on classes that might use them. 
Since this was just a sandbox for me, no harm was done but I now believe that I
was incorrectly providing class inferences based those ___domain statements. 
My thinking now is that these types of properties should really never have a
___domain specified since it is very likely that such properties will be used on a
wide variety of classes.  Is there a flaw in this statement?
 
Thanks in advance for your thoughts on this.
 
Matt
 
 
 
 
 
 
 
[1] Dean Allemang and Jim Hendler. 2008.