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Re: A shot at http://www.w3.org/2000/03/rdf-tracking/Overview.html#rdfms-resource-semantics

From: Frank Boumphrey <bckman@ix.netcom.com>
Date: Fri, 11 May 2001 00:11:21 -0400
Message-ID: <00f301c0d9d0$73da86a0$9acd79a5@preferreduser>
To: "Brian McBride" <bwm@hplb.hpl.hp.com>, "Martyn Horner" <martyn.horner@profium.com>
Cc: <w3c-rdfcore-wg@w3.org>
> Its exactly this sort of confusion that we need to clear up.  I
don't
> believe there is a question here, though there does tend to be some
> confusion about this.  For example, RFC 2396 is quite clear that a
resource
> is NOT the bit sequence (or actual atoms).

This is exactly right. I am a resource described by my name. The fact
that i can also be described by my DNA sequence (unknown at present)
does not make me less of a resource just because my DNA sequence
_is_unknown. When my DNA sequence is known you will probably still
carry on describing me by my name, not my DNA sequence.

> Lets try and stay away from the legal stuff if we can.  The law is
for
> lawyers - we are writing specs - not Acts of Parliament, Bills for
Congress,
> or whatever the equivalent is in your locale

I agree

> Resource is a term widely used in the internet and on the web.  Lets
be
> careful about confusing everyone by having an incompatible
definition.
>

Again I agree. I (in my simple way) _know_ what a resource is. Let's
not make the definition so complex that I (or my consituency, the
common-or-garden HTML writer) become confused.

>   i.e. two resources are identical if they have the same URI.
>   two resources with different URI's are different resources.

Again i agree. To stretch my earlier analogy. Identical twins have
identical DNA, and yet they are different entities or resources.

Two URLs may be identical down to the last byte, but they are
different, and have their own identities.

Frank
----- Original Message -----
From: "Brian McBride" <bwm@hplb.hpl.hp.com>
To: "Martyn Horner" <martyn.horner@profium.com>
Cc: <w3c-rdfcore-wg@w3.org>
Sent: Tuesday, May 08, 2001 8:43 AM
Subject: Re: A shot at
http://www.w3.org/2000/03/rdf-tracking/Overview.html#rdfms-resource-se
mantics


>
>
> Martyn Horner wrote:
>
> >
> > It's clear that the definition of resource in the M&S spec is
intended
> > to be a `fundamental' definition from which the rest can be built.
>
> Yes, that why its scheduled early.  We need a clear working model
for how we
> understand resources.  But I'm hoping to avoid a philosophical death
spiral
> on this one.  We need a model of resources that is sufficient to
enable us
> to progress.
>
> > It's
> > clear also that there's a question whether a `resource' as
understood in
> > RDF represents the bit-sequence (or the actual atoms) of a
referenced
> > entity or some sort of pledged token of good intent towards an
> > significantly-invariant object.
>
> Its exactly this sort of confusion that we need to clear up.  I
don't
> believe there is a question here, though there does tend to be some
> confusion about this.  For example, RFC 2396 is quite clear that a
resource
> is NOT the bit sequence (or actual atoms).
>
> >
> > I wonder, given the need to emphasise the legal aspects of RDF
> > assertion, whether we don't need to define resources reflexively
to
> > support this.
>
> Lets try and stay away from the legal stuff if we can.  The law is
for
> lawyers - we are writing specs - not Acts of Parliament, Bills for
Congress,
> or whatever the equivalent is in your locale.
>
> >
> > I was playing with a definition along the lines of `a token for an
> > object constrained in a set of dimensions expressed by a set of
> > properties and values but otherwise capable of redefinition'.
>
> Hmmm.  Might be a good idea to start with whatever definitions
already exist.
>
> > There's a
> > musing somewhere which talks about successive degress of
specificity in
> > a web reference. Using `isVersionOf' and
`isLanguageSpecificVersionOf'
> > allows resources to inherent a set of dimensional constraints from
> > another resource or to have them selectively relaxed.
>
> Where?  How authoratative are they?
>
> >
> > It seems to me that, to reflect the spirit of the Semantic Web, we
> > should help to define the handles on the system in ways that allow
(and
> > encourage) fullfillment rather than impose limitations. Defining
> > resources by their role in RDF (and not RDF as a process on
resources)
> > both expresses the spirit and allows a rigorous `external'
description
> > of `assertion'. It means that `resources' get an RDF-specific
> > definition.
>
> Resource is a term widely used in the internet and on the web.  Lets
be
> careful about confusing everyone by having an incompatible
definition.
>
> What I'm hoping for here is something pretty simple that can serve
as a
> foundation on which we can build.
>
> I recently tried to articulate the working model that I use and it
came
> out something like this:
>
>   There is a set of resources R.
>
>   Each member of R is identified by a URI by which I mean:
>
>     r1.uri == r2.uri <=> r1 == r2
>
>   i.e. two resources are identical if they have the same URI.
>   two resources with different URI's are different resources.
>
>   There is a set E of entities.  Entities are things like web pages,
>   numbers and trees in the park.
>
>   There is a mapping D : R -> E.  i.e. there is mapping which maps
resources
>   to entities.
>
>   There is a notion of equivalence.
>
>   Two resources r1 and r2 can be mapped by D to the same entity.  In
that case
>   we say they are equivalent.
>
>     equiv(r1,r2) <=> D(r1) = D(r2)
>
>   and finally:
>
>     D((p,s,o)) <=> D(p)(D(s),D(o))
>
> I present this, not because I claim it is correct, it doesn't deal
with frag
> id's
> for example, but to suggest a language in which we can be clearer
about
> what we mean.
>
> Brian
>
>
Received on Friday, 11 May 2001 00:01:04 EDT

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