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Re: I-D ACTION:draft-masinter-dated-uri-00.txt

From: Sean B. Palmer <sean@mysterylights.com>
Date: Sun, 26 Aug 2001 15:25:04 +0100
Message-ID: <008201c12e3b$0c0fe140$91ed93c3@Palmer>
To: "Larry Masinter - LMM@acm.org" <lmnet@attglobal.net>
Cc: <uri@w3.org>, <www-rdf-interest@w3.org>
> I wrote this up for discussion purposes, as a response
> to some of the discussion about URNs, URIs, and the
> difference between abstractions and resources that
> describe them. [...]

I'm confused as to the distinction between "duri" and "tdb". One identifies
the representation of the resource, and the other represents the resource,
fine, but I think you've confused the issue terribly by some of the
examples in your draft:-

> For example,
>    urn:tdb:2001:data:,The%2520US%2520president
> names the concept described by the (text/plain) string
> "The US president" at the very first instant of 2001.

The resource referred to by the URI data:,The%2520US%2520president at any
moment in time is simply the string "The US president". You're confusing
the lexical value of a definition of a resource with the resource itself.
The concept *of* "The US president" is not *ever* identified by that URI.
Hence, the "data:" URI scheme is "persistent" because its own particular
context doesn't change, and therefore using a "tdb" on it is pretty

"tdb" is neat for preserving context. The context of a URI that actually
does identify the current U.S. president (which could be a URN, as URI and
URN are basically interchangable [1]) is something that does change over
time, and that a "tdb" would be neat for preserving. So I think that the
scheme is valid, but that the particular example above is misleading and
simply incorrect.

[1] I will claim that until someone can provide me with a quantitative
defintion of how URNs are "more persistent" than any particular URI scheme.
The persistence of a URI is given by the context of its use, and that's not
something which can be accurately modelled.

Kindest Regards,
Sean B. Palmer
@prefix : <http://webns.net/roughterms/> .
:Sean :hasHomepage <http://purl.org/net/sbp/> .
Received on Sunday, 26 August 2001 10:25:27 GMT

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