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Re: Identifying Things (on the semantic web)

From: Ralph R. Swick <swick@w3.org>
Date: Wed, 24 Jan 2001 07:03:35 -0500
Message-Id: <200101241828.NAA03553@tux.w3.org>
To: Sandro Hawke <sandro@w3.org>
Cc: www-rdf-logic@w3.org
At 04:27 PM 1/19/2001 -0500, Sandro Hawke wrote:
>
>The problem: How do you talk about something when you don't already
>share with your audience a common identifier for it?
>
>Proposed answer: Find a document which 
>  - can be identified to your audience
>  - contains some text which, in the document, identifies
>    the thing in a way your audience understands.
>
>Then identify the thing with the pair (document identifier, text of
>thing-identifier).

Indeed, the XML Topic Map (http://www.topicmap.org/) folk have
a name for such a document: "Subject Indicator Resource"

See, http://www.topicmaps.org/xtm/1.0/xtm1-20001204.html#conceptualmodel

(Bizarrely, IMHO, I was told by one of the XTM folk that they really
do mean to require that an instance of a Subject Indicator Resource
contain *only* human-interpretable text.  But that's another matter.)

The XTM Subject Indicator Resource is expected to uniquely
identify the 'thing'.  This in itself is an important semantics but
would appear to be hard to verify.

>I think people have been trying to approximate this by using
>identifiers like
>   http://www.ietf.org/rfc/rfc2396.txt#URI-reference

Be careful about presuming intent.  You may choose to present
this identifier to the Web and issue a GET message in HTTP
and decide if the response is useful to you, but this operation
(asking the Web for additional information) is independent of
whether the "owner" of the identifier (probably IETF in this case)
meant it to refer to some concept of URI fragment reference or
to some sequence of octects.

[I am travelling and mostly off-line as I am writing this, so
apologies for the time lag and for any duplication if someone
else has already noted this here.]

-Ralph
Received on Wednesday, 24 January 2001 13:28:19 GMT

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