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Re: What is at the end of the namespace? (and where to use RDDL)

From: Sean B. Palmer <sean@mysterylights.com>
Date: Mon, 19 Nov 2001 16:58:45 -0000
Message-ID: <01dc01c1711b$90749660$d1d993c3@localhost>
To: "Al Gilman" <asgilman@iamdigex.net>
Cc: <uri@w3.org>
> Search URLs are much better explained as clauses
> restricting a kind of stuff sought, rather than articulating
> a reference to a thing with identity.

I'm not so sure about that. When I hand someone a reference to a
search engine result, the notion of what I expect that reference to
denote is bound purely by the context [1] in which this transaction
takes place. I've been arguing that for quite some time now, and it
seems to me to be the most practical way of modelling how URIs, and
especially HTTP URIs, are used in real life.

And even a clause is something with identity. What I mean is that
you're saying that one slice of the way in which URIs are interpreted
is better than another slice. I don't really buy into that.

> A resource is something of potential utility.

A resource, or a potential/candidate resource? I'm sure that there is
a clause that means we have to make a distinction between the things
that are resources in the URI sense, and other things which have
identity, but which are not yet denoted by URIs (perhaps this is in
Sandro's notes [2] somewhere). In this case, I think you're absolutely
correct.

> [...] Anything which will likely increase your return rate
> on a direct-mail solicitation is a valuable information
> resource.  And there are ways to refer to such a resource
> which are the more effective for not identifying the data
> that is eventually bound to the transaction.

Well, that's a different kind of identification... identification by
procedure I guess, rather than identification by description or
abstraction. Sandro has argued that that's still on the same
wavelength as naming. Aaron has argued that using procedural
identification in the HTTP space is *not* a purely definitive method
of gaguing the semantics fo the resource:-

   http://ilrt.org/discovery/chatlogs/rdfig/2001-09-20.html#T15-35-02

I agree, and am reminded of one of Larry Wall's witticisms:-

   "Odd that we think definitions are definitive. :-)"
     - Larry Wall, <mid:199702221943.LAA20388@wall.org>

As if I need to beat this point any further, try "Re: URI Resolver":-

   http://lists.xml.org/archives/xml-dev/200103/msg01053.html

I don't even really agree that a URI can be in any sense "defined" by
some common procedure that it is used in, yet alone that the
definition is not definitive. It's just a common procedure.

> Search URLs are useful in that they restrict the manner
> of stuff sought by a [network remote] agent, while leaving
> the identity of what the search agent references in its
> response up to the search service.

To some extent I would not want the binding from the URI to the
resource to break. Deciding just how broad that extent is is left an
an exercise for the reader... but I think that it is common to refer
to a search result as "the current results for a search using the
string 'blargh' at this well-known Web service". I would not want that
binding to break, and therefore I think it is the least acceptable
level of persistence for a search result URI.

While that may seem contradictory to what I have been arguing so far,
you can think of it as setting a practical bound on how URIs are
interpreted when used... or rather, as expressing those bounds. In
other words, when I take a certain set of definitions to be persistent
(say, the server that I use to get information back [procedure], the
concept binding by the author of the URI, or the most plausible
persistent common use), I do so because I want to "use" a URI rather
than debate over what they identify for years on some W3C mailing
list.

> Semantically, it is closer to universal truth to describe
> URIs as a Unified-syntax Resource Indication than
> Uniform Resource Identifier [...]

I've always wanted "Universal Resource Indicator" :-)

> [...] The restriction of URI-referends to things with identity
> does not add value, has not been used, and historically could
> be viewed as 'lost.'

I would disagree with you here had you left the word "restriction" out
:-) As it is, I agree that the restriction doesn't add value, and
could not add value. Sometimes, you want to say "go and dereference
this URI, the result a neat quote on it" (or often, go look at "x"!).
That is a highly valid use of a URI, and I'm not debating that.

> It is long past time that we should have lost the idea that
> URIs only indicate resources of definite identity, only things
> and not stuffs, from our baseline of working hypotheses
> about this most excellent invention.

O.K., I agree with your conclusion, but I would caution you to be
careful in opening the spectrum up that you don't give the impression
that you're willing to restrict URIs in another way, into procedural
identification.

> ** Do use RDDL, but not bound to the namespace name.
>
> The namespace name is a bad place to refer to RDDL.

What's a "namespace"? Seriously. They don't even exist (as the
entities that people seem to think they are) in RDF. That is the
original seed of the discussion.

[1] "Context" is a bad word for it, and I'm continually searching for
a better one.
[2] http://www.w3.org/2001/03/identification-problem/

--
Kindest Regards,
Sean B. Palmer
@prefix : <http://webns.net/roughterms/> .
:Sean :hasHomepage <http://purl.org/net/sbp/> .
Received on Monday, 19 November 2001 12:00:05 GMT

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