W3C home > Mailing lists > Public > www-tag@w3.org > July 2003

[metaDataInURI-31] targets of sentences, was Re: Initial draft finding for public review/ comme nt.

From: Jonathan Borden <jonathan@openhealth.org>
Date: Mon, 14 Jul 2003 15:54:54 -0400
Message-ID: <00c301c34a41$cf2a4750$b6f5d3ce@svhs.local>
To: <www-tag@w3.org>

Let me expand on this a bit.

> Roy T. Fielding wrote:
>
> >
> > The resource referred to by the URI does not vary.  What varies is the
> > target that is ultimately referred to by the "sentence" surrounding the
> > URI referral.
>

As we all know: "A resource can be anything that has identity. "

Since the target of a sentence might have identity, such a target might
certainly be a resource. For example, let's assume the "SSN" scheme for a
social security number URI e.g.

ssn:012-34-5678

now, the resource which is identified by such a URI might be a "social
security number"

Do such URIs uniquely identify American citizens? Err, not actually because
(unfortunately) the U.S. Social Security Administration reuses SSNs (as
people die off, the numbers might be recycled).

At any given date/time, the SSN _does_ identify a single person, so assume
the sentence.

The person identified by ssn:012-34-5678 at July 14, 2003.

The _target_ of such a sentence is a person who is uniquely identified by
the URI in the context of the sentence. We've not assigned a URI to this
person even though the person has _identity_ given the sentence. I'd say
that this person is surely a resource in the RFC 2396 definition.

This type of resource directly corresponds to the RDF "anonymous resource"
or "b-node". Thus RDF b-nodes seem to be what Roy describes as the target of
a sentence. I will go as far as to say that most if not all interesting
resources are anonymous. By this I mean that the resources which are
directly identified by a URI tend to be placeholders for the URI itself
(i.e. "social security numbers"). Resources of the scheme "mailto" probably
never are intended to actually identify a person, rather a person is be
uniquely identified by a mailto:joe.smith@example.org URI. These are  OWL
InverseFunctionalProperty's: the mailbox identifies it's owner in an N:1
fashion

Jonathan
Received on Monday, 14 July 2003 15:55:01 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:55:59 UTC