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Re[2]: true/false in RDF?

From: David Powell <djpowell@djpowell.net>
Date: Wed, 16 Mar 2005 23:45:09 +0000
Message-ID: <1887616932.20050316234509@djpowell.net>
To: "Joshua Allen" <joshuaa@microsoft.com>
CC: "Geoff Chappell" <geoff@sover.net>, "Danny Ayers" <danny.ayers@gmail.com>, "Seth Russell" <russell.seth@gmail.com>, <semantic-web@w3.org>

Hello Joshua,

Wednesday, March 16, 2005, 11:02:20 PM, joshuaa@microsoft.com wrote in mid:0E36FD96D96FCA4AA8E8F2D199320E5204883C09@RED-MSG-43.redmond.corp.microsoft.com :

>> > unspecified?  And of course, all of it means I *need* RDFS (and
> OWL),
>> > *everywhere*.  Why take such a huge dependency if you don't need to?
>> So if you have 8 boolean properties, you need a minimum of 8 classes
> (or

> If I use Boolean URIs, I don't need *any* classes.

> I'm struggling to see the value in modeling this in any way that
> requires more than zero classes (or OWL) to be defined.


  <http://foobar/page.html> <rdf:type> <urn:myterms:CachedObject>

isn't any more difficult that using:

  <http://foobar/page.html> <urn:myterms:isCached> <http://xmlns.com/wordnet/1.6/true>

The class <urn:myterms:CachedObject> is just a resource in the same
way as a Boolean URI such as <http://xmlns.com/wordnet/1.6/true> is a
resource. It would be good practice to declare the class in some RDFS,
but it wouldn't be wrong if you don't.

In fact, if you were using an RDFS reasoner, then I guess that the
presence of an rdf:type property in your graph would implicitly
declare the class due to the range of the rdf:type property being

Using classes to represent boolean properties seems like a better RDF
idiom than using boolean properties.  It also makes it easier to
document the properties using RDFS if you want to.

Received on Wednesday, 16 March 2005 23:45:42 UTC

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