RE: [VM] TAG clarification on 302 vs 303, PURLS and more...

One other question I think we should specifically ask the TAG for
clarification . . .

> > From: Miles, AJ Alistair)
> > . . .
> > 1. The class of 'information resources'.
> > 
> > It would be useful if the TAG were to coin a URI for the class of 
> > 'information resources' . . . .
> > 
> > The implied TAG position is that the meta-classes rdfs:Class, 
> > owl:Class and rdf:Property are all disjoint with the class 
> > tag:InformationResource, and therefore expected HTTP behaviour for 
> > members of these meta-classes is clearly specified by the TAG 
> > resolution on httpRange-14 [5] (i.e. they MUST return 303).

Is tag:InformationResource owl:disjointWith anything?  If so, what?

The TAG's httpRange-14 decision[5] seems to say that a 2xx response from
a URI such as http://example.org/xyz should be interpreted as
authoritatively asserting something like:

	http://example.org/xyz rdf:type tag:InformationResource .

However, should it also be interpreted as authoritatively asserting that
http://example.org/xyz is *not* also something else, i.e., that
tag:InformationResource is owl:disjointWith something else?

The URI minting rule described in the httpRange-14 decision[5] says that
the rule is "for the sake of removing ambiguity".  But asserting that
http://example.org/xyz *is* a tag:InformationResource only removes
ambiguity in a *closed* world, because it allows one reach a different
conclusion depending on whether an assertion is known to be true or not
known to be true.  Under the open world assumption, no ambiguity is
removed unless being a tag:InformationResource *also* implies
http://example.org/xyz is *not* something else, i.e., unless
tag:InformationResources is owl:disjointWith something else.

[5] http://lists.w3.org/Archives/Public/www-tag/2005Jun/0039.html

David Booth

Received on Monday, 30 January 2006 15:32:57 UTC