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Re: What a URI means, was Re: erratum Re: resources and URIs

From: Jonathan Borden <jonathan@openhealth.org>
Date: Fri, 25 Jul 2003 11:22:01 -0400
Message-ID: <0b4c01c352c0$8722d030$b6f5d3ce@svhs.local>
To: "pat hayes" <phayes@ihmc.us>, "Roy T. Fielding" <fielding@apache.org>
Cc: <www-tag@w3.org>

Roy T. Fielding wrote:

> REST resources are always information resources, not because the
> resources are information, but because the system is designed to
> retrieve information associated with any resource identifier.
>
and
>
> ... The resource
> in REST is the conceptual mapping, not the concept.  The concept
> can exist outside the REST-based system and be uniquely identified
> by the same URI outside the system.

Thanks, that is a huge clarification for me. This makes terrific sense.

> ... Claiming that the URI cannot
> identify both the conceptual mapping and the real thing outside
> the information system is equivalent to claiming that your
> social security number cannot be used to identify anything other
> than your social security account.  REST-based systems use URIs
> as indirect identifiers, even if they happen to identify
> the same thing directly.

In OWL we have an exact way of describing a concept that is uniquely
identified by a URI. This is called an owl:InverseFunctionalProperty -- the
property e.g. SSN, uniquely identifies the person it is 'attached' to.

It is helpful to distinguish between the three distinct things 1) the SSN 2)
the social security account, 3) the person. Indeed all are identified by the
SSN, the first is an identity relationship, the other two are indirect (yet
still exact) relationships.

I think it is helpful to make this distinction -- if for no other reason
that it reduces the confusion among human readers of the specification.

It would be great if the webarch document can incorporate this distinction.

Jonathan
Received on Friday, 25 July 2003 11:22:21 UTC

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