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Re: "On the Web" vs "On the Semantic Web"

From: Jonathan Borden <jonathan@openhealth.org>
Date: Sat, 26 Jul 2003 10:51:49 -0400
Message-ID: <0cd101c35385$7509acf0$b6f5d3ce@svhs.local>
To: "Norman Walsh" <Norman.Walsh@Sun.COM>, <www-tag@w3.org>
Cc: "pat hayes" <phayes@ihmc.us>

Norman Walsh wrote:

[good stuff snipped]
>
> Now I can distinguish between the two, but I don't often find it
> necessary or interesting to do so. I assert that
> http://norman.walsh.name/knows/who#norman-walsh identifies my physical
> person. As it turns out, you can get either HTML or RDF
> representations of me directly over the web. I don't see why it's
> important to distinguish between me and the apache server process on
> the machine in my closet that's acting as my proxy and returning
> representations of me. But if I did, I could give it a distinct name
> too.

Good point. This URI when dereferenced as Accept: application/rdf+xml might
return:

<rdf:Description rdf:ID="norman-walsh" />

and when dereferenced as text/html might return:

<div id="norman-walsh> ... </div>

It seems to me that using a URIref has the same issue as a URI: does it
identify the RDF Description or the XML that forms the RDF Description (i.e.
the abstract concept vs. the document that describes the abstract concept).

Now an RDF application has no problem, because in the *context* of RDF
semantics, the meaning of the URIref is one thing, but in the context of
HTML the meaning might be something else.

So where does that leave us with respect to "document about weather in
Oaxala" vs "concept weather in Oaxala" -- it seems to depend on how we
define it. What prevents someone from saying:

<http://weather.example.com/oaxaca> rdf:type web:document .

or *instead* saying:

<http://weather.example.com/oaxaca> rdf:type ex:weatherLocation .

The SW treats URIs as opaque. The current Web doesn't care about what the
range of HTTP URIs is. What is the actual physical purpose of making this
distinction?

Pat suggests that SW agents need to know. If so we can use assertions to
tell them.

Jonathan
Received on Saturday, 26 July 2003 10:52:01 UTC

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