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Re: "On the Web" vs "On the Semantic Web" (was Re: resources and URIs)

From: pat hayes <phayes@ihmc.us>
Date: Mon, 21 Jul 2003 18:08:40 -0500
Message-Id: <p06001a06bb42192831ce@[]>
To: Michael Mealling <michael@neonym.net>
Cc: Tim Bray <tbray@textuality.com>, www-tag@w3.org

>On Sat, 2003-07-19 at 16:34, pat hayes wrote:
>>  >Michael Mealling wrote:
>>  >
>>  >>In my 'layered' view, the SW is a layer above the web, and as such a SW
>>  >>'resource' contains at its heart, a Web resource. You _could_ think of
>>  >>it this way: it's the same object with multiple interfaces, the
>>  >>Uri-Resource view found in 2396 being the equivalent of an IUnknown
>>  >>interface (just without the ability to query for  the other
>>  >>interfaces)'. As you go up the layers you end up with more available
>>  >>interfaces to pick from....
>>  >
>>  >I have a lot of sympathy with this world-view.  Is there anyone who
>>  >really doesn't like it?
>>  I really don't like it, for one. I don't see the SW as being in a
>>  layer above the Web, and the only way I can make sense of this seems
>>  to suggest a misunderstanding of the aims of the SW; that is is
>>  supposed to be in some sense a new kind of meta-data about the Web
>>  itself.  If y'all have that idea in mind, please try to put it out of
>>  your mind. SW technology *could* be used that way, but that is not
>>  the primary or intended use case for the technology.
>That's a fine point of view. But what I'm after with the idea of layers
>is that there is a layer boundary between the Web (the definition I'm
>using is "that set in which each member is identified by a URI") and the
>Semantic Web

I know that's what you are after, but Im here to tell you that there 
is no such layer boundary. Your definition applies better to the SW 
than to the Web, by the way.

>such that other application that use URIs are never
>impacted by the fact that the SW either exists or does not exist.

Well, they may not be, though the ones that are so 'impacted', ie 
which make good use of SW technology, will almost certainly beat out 
the others in the B2P and B2B markets pretty damn quickly.

>means that 2396bis and its definitions, which work just fine for other
>very deployed applications,

But do they, in fact? Consider just HTML and http:  URIs for the 
moment, and pretend that the SW was still just a gleam in TimBL's 
eye. It seems to me that RFC2396 *still* doesn't make sense.  It says 
for example that a resource is 'anything with an identity', that each 
URI must identify a single resource, and that (barring network 
problems, etc) the URI enables one to perform operations on the 
resource. OK, take that at face value, and check out the URI
What is the resource identified by that URI? In what possible sense 
could this URI enable me to perform an operation on a resource?  Is 
what I just did impossible, or illegal, or just plain naughty? Or is 
RFC 2396 calling me a liar?

>  is left completely as is. In network
>engineering that's called a 'layer boundary'.
>>  BTW, the current usage of "resource" in the SW specifications is
>>  vacuous: a SW Resource can be anything whatsoever, real or imaginary,
>>  on or off the Web, in the past or future, of any nature, with or
>>  without a URI. So to claim that all SW resources 'contain' a Web
>>  resource sounds like it would also have to be vacuous or else would
>>  be obviously false (depending on what a 'web resource' is, which of
>>  course I have no idea about, this never having been defined or
>>  elucidated anywhere.)
>And that's fine as well. Nothing in my layer view suggests that there is
>a one to one mapping between a SW resource and a URI-Resource....

What is the nature of this distinction between SW resources and 
URI-resources? The SW uses the same URIs that the rest of the Web 

>  > I have no idea what an interface to an object could possibly be.
>>  What kinds of interface do the following objects have: a grain of
>>  sand, a galaxy, an imaginary detective ?
>I'm comfortable with electronic proxies for physical things.

So am I, but I would like to be clear when Im talking about the thing 
and when about the proxy; particularly if the proxy in fact is a 
symbol referring to the thing its the proxy of.

>... Hell, I
>registered a URN namespace that is explicitly limited to identifying
>human beings and aggregates of human beings. I've written several
>electronic interfaces to them as well. It all seems to work just fine.
>>  PS.  Reading things like this makes me wonder whether you guys
>>  inhabit the same planet as the rest of us. Things with hearts and
>>  multiple interfaces, arranged in layers...?? What the hell are you
>>  talking about??? Here I am looking out of my window at an oak tree
>>  and I wonder if its a resource, and what its interfaces could be, and
>>  what layer it would be in.... and then I decide that none of this
>>  makes the slightest sense. Unfortunately, that is the only conclusion
>>  I am left with, yet again.
>Its called network engineering. Ever done any of it?

No, but I do hang out with folk who have from time to time; and if 
what some of y'all are saying about resources and identifying and 
links and so on is true, we aren't talking just about network 
engineering: we are talking about reference and denotation. (Do 
network engineers usually spent much time worrying about oak trees?) 
That is semantics, and I have done a fair amount of semantics. Let me 
ask you in response, have you done any semantics? The relevance of 
which is that I'm not asking you to rewrite anything about network 
engineering or architecture; I'm only asking y'all to not make 
assertions *about semantics* that don't make semantic sense.



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Received on Monday, 21 July 2003 19:08:43 UTC

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