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Why distinguish entity vs. resource was: Re: [URI vs. URIViews] draft-frags-borden-00.txt

From: Jonathan Borden <jonathan@openhealth.org>
Date: Sat, 23 Feb 2002 00:33:34 -0500
Message-ID: <03e101c1bc2b$a5503fc0$0301a8c0@ne.mediaone.net>
To: "Pat Hayes" <phayes@ai.uwf.edu>
Cc: <me@aaronsw.com>, <www-rdf-comments@w3.org>
>
> I think there are still some serious issues to sort out in this area,
> both within RDF and more generally.
>
> Pat
>

Agreed. It is important that we keep these terms straight because without a
proper _shared_ meaning for resource, entity etc, RDF is like defining math
without a common agreement for which symbols represent the first, second and
third integers.

It is not immediately obvious why the distinction is made between a resource
and the network entity that represents.

Imagine the resource that represents "Pat Haye's resume", you give it a URI:

http://pat.hayes.org/resume/

Now suppose the Web had existed throught your early career. The actual
document returned by referencing the URI would change from time to time as
additions are made to the resume.

The document returned by HTTP GET is termed an _entity_, this is said to
represent a resource. Certainly if I donwload this document, and edit it, I
am not editing _your resume_, rather I am editing a _representation of your
resume_.

It is for this reason that the level of indirection between a resource and
an entity is made.

Another example might be the current stock price of Intel:
http://nasdaq.com/ticker=INTC

You see that the Web started out with resources that were classed as vaious
types of documents, e.g. "resume" "home page" etc, The desire is to use
resources things not directly connected to the Web, nor easily serializable,
such as a "person" or a concept such as "Unicorn", such resources are termed
"abstract resources".

While an abstract resource is not connected to the Web, a _representation_
of such a resource easily may be, e.g. a picture of you is available at a
given URI, or a picture of a Unicorn is available at
http://example.org/Unicorn. So again, the HTTP GET returns the
representation i.e. the entity, not the resource.

Does this make any sense?

Jonathan
Received on Saturday, 23 February 2002 00:28:15 GMT

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