W3C home > Mailing lists > Public > www-rdf-interest@w3.org > December 2003

Re: Trust, Context, Justification and Quintuples

From: Dan Brickley <danbri@w3.org>
Date: Tue, 30 Dec 2003 19:54:34 -0500
To: Andrew Newman <anewman@pisoftware.com>
Cc: www-rdf-interest@w3.org
Message-ID: <20031231005434.GH8594@w3.org>

* Andrew Newman <anewman@pisoftware.com> [2003-12-31 10:19+1000]
> 
> > as one statement with two sources or as two different statings?
> > Jeremy was referring to this problem as "the old statement/stating
> > discussion" earlier in this threat. Maybe he can give us a link to some
> > documentation about the pros and cons of the two different views.
> >
> 
> While, I still haven't caught up on this conversation I thing the whole
> statement/stating discussion is summarized here:http://www.ilrt.bris.ac.uk/discovery/2000/11/statements/

That was a good summary at the time. Since then, the RDF Core WG has
done a bit of tidying up. The latest word on reification is now:
http://www.w3.org/TR/rdf-mt/#Reif

The most subtle point w.r.t. reification is that the values of the 
rdf:predicate, rdf:subject, and rdf:object properties are 
things rather than terms denoting those things. This has knock-on 
effects for anyone aspiring to track provenance etc of data using just 
these constructs. The specs says:

	...the reification describes the relationship between a token of a triple
	and the resources that triple refers to. The reification can be read
	intuitively as saying "'this piece of RDF talks about these things"
	rather than "this piece of RDF has this form".

This interacts with facilities such as OWL's mechanism for indicating 
'sameAs' relations and other forms of identity reasoning, so one needs to
be careful not to read too much into RDF reification vocab assertions...

Dan
Received on Tuesday, 30 December 2003 19:54:34 GMT

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