W3C home > Mailing lists > Public > www-rdf-interest@w3.org > April 2003

RE: URI for language identifiers

From: <Patrick.Stickler@nokia.com>
Date: Thu, 3 Apr 2003 10:10:52 +0300
Message-ID: <A03E60B17132A84F9B4BB5EEDE57957B5FBB60@trebe006.europe.nokia.com>
To: <pfps@research.bell-labs.com>
Cc: <miles@milessabin.com>, <www-rdf-interest@w3.org>

> > >From http://www.ietf.org/rfc/rfc2396.txt
> > [
> >    3.2. Authority Component
> > 
> >    Many URI schemes include a top hierarchical element for a naming
> >    authority, such that the namespace defined by the 
> remainder of the
> >    URI is governed by that authority.  This authority component is
> >    typically defined by an Internet-based server or a 
> scheme-specific
> >    registry of naming authorities.
> > ]
> > 
> > where a "naming authority" is that agency which (either directly or 
> > indirectly) mints a URI and defines its denotation -- i.e. 
> which names 
> > a resource by a URI.
> >
> > That authority either equates to, or may designate, the 
> creator (owner) 
> > of a given URI and it is the creator which specifies what 
> the URI denotes.
> 
> Where in this is there anything that talks about the denotation of a
> URI reference?  

I'm presuming that the term 'naming authority' is not there just
for filler. And that what is being named is a resource, and the
name is the URI.

> This quote also mentions that governance for namespaces is 
> only for ``many
> URI schemes''.  What about the others?

Not all URI schemes allow for arbitrary denotation. Some schemes
(e.g. data:, val:, issn:, etc.) fix the denotation according to
semantics defined by the scheme itself. Thus, even if there were
an owner for e.g a val: URI, they would not be able to change
the denotation of that URI as it is fixed by the URI scheme to
be whatever datatype value is denoted by the pair of lexical form
and datatype.

And just because not *every* URI scheme has a clear authority
component, that doesn't mean that those for which there *is*
an authority component do not base ownership on that component.

> > True, the actual agency is indirectly identified by the 
> naming authority
> > component of the URI scheme, being e.g. the owner of a 
> given domain name,
> > IP address, registry domain, etc. but the identity of the agency is
> > clearly determinable.
> > 
> > And even if the determination of ownership for a given URI may take
> > some investigation -- for any given user, it should be clear when
> > they *don't* own a given URI, and thus should look to the owner for
> > what it denotes. 
> 
> Again, what does naming governance have to do with denotation?  

Err.. naming is the act of defining the denotation of the URI. One names
a resource with a URI, thereby setting the denotation of that URI.

So the naming authority is the agency which specifies the denotation of the URI.

> > This issue has been explored at length by the RDF Core WG and (while
> > not to be included in the final specs, but in a separate 
> publication)
> > the discussion regarding the meaning of URIs authored by the WG is
> > illustrative of the shared view of many members of the SW community:
> > 
> > >From http://www.w3.org/TR/rdf-concepts/#section-Social:
> > [
> >    4.3 Authoritative Definition of Terms
> > 
> >    The social conventions surrounding use of RDF assume 
> that any RDF URI 
> >    reference gains its meaning from some defining 
> individual, organization or 
> >    context. This applies most notably to RDF predicate URI 
> references. 
> > 
> >    These social conventions are rooted in the URI 
> specification [URI] and 
> >    registration procedures [URI-REG]. A URI scheme 
> registration refers to a 
> >    specification of the detailed syntax and interpretation 
> for that scheme, 
> >    from which the defining authority for a given URI may be 
> deduced. In the 
> >    case of http: URIs, the defining specification is the 
> HTTP protocol 
> >    specification [HTTP], which specifies how to use the 
> HTTP protocol to obtain 
> >    a resource representation from the host named in the 
> URI; thus, the owner of 
> >    the indicated DNS domain controls (observable aspects 
> of) the URI's meaning. 
> > 
> >    Thus, the choice of terms used in published RDF is 
> significant in determining 
> >    its meaning, through reference to definitions asserted 
> by the defining 
> >    authorities for those terms. 
> > ]
> > 
> > Thus, the views that I have been expressing here are both 
> reflected in 
> > the URI specs as well as reflect common opinion in the SW community.
> 
> A unanimous decision of the RDF Core WG
> (http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Mar/0068.html)
> struck the entire social meaning section from this document, 
> so referring
> to it doesn't carry much weight.  I haven't heard of any separate
> publication from the RDF Core WG on this issue.  

Perhaps you should re-read my comments given in introduction to
the above quote, rather than simply taking it out of context.

(a) I stated myself that the quoted section was not included in
the latest drafts of the RDF specs. I was in fact the person who
proposed that the section be removed from the spec (though not
because I did not agree with its content).

(b) The quote reflects a very common view about URI ownership
and authority, and that was my clearly stated purpose for giving
that quote.

Furthermore, the section was removed because (a) there was not
sufficient consensus about certain points (not including URI
authority IMO) that require additional discussion and (b) as that
section was not critical to the rest of the RDF specs, it was
removed so that the process would not be held up while those
particular points needing further discussion are addressed.

> > > > And any disagreement about the denotation of a given 
> URI utimately
> > > > must be resolved by the owner of that URI.
> > > 
> > > Hmm.  Where does the notion of the (unique) owner for 
> (every) URI come
> > > from?   For example, who is the owner of
> > > 	http://www.bellllabs.com/user/pfps/#me
> > 
> > I couldn't say. Though to find out, I'd first contact the owner of 
> > the domain www.belllabs.com, and I'd expect I'd likely be told that
> > the sub-webspace http://www.belllabs.com/user/pfps/ was controlled
> > by you, and that all URIs grounded in that sub-webspace are under
> > your ownership. Therefore, you are probably the owner of the URI
> > http://www.belllabs.com/user/pfps/#me and if I wanted an 
> authoritative
> > definition of what that URI denotes, I'd ask you specifically.
> > 
> > Is that really so difficult?
> 
> Yes, as www.bellllabs.com is not a registered domain.

Well, then it is an invalid URI and you are just yanking my chain.

Shame on you.

I presume that we are talking about valid URIs.

> > > Even if there is an owner of a URI, how does that owner 
> > > determine what a
> > > URI means?  
> > 
> > The issue is not *how* the denotation of a given URI is defined,
> > but *who* has the right to define it.
> 
> Huh?  If there is no means for determining the denotation of a URI
> reference, then I don't see how this scheme can possibly 
> work.  Are you
> proposing, for example, *the* denotation of a URI reference *could* be
> determined by the thoughts of a dead individual?

Boy, you really do want this to be complicated, don't you. 

(a) if one cannot determine the ownership of a given URI such that one
    cannot reliably determine the authoritative denotation of the URI,
    then the URI cannot be reliably used. Period. Use or create another.

(b) if the known owner of a given URI is dead, and there is no information
    remaining from that individual which sufficiently clarifies the denotation
    of the URI, then that URI has effectively died with that person.

> > > Even if there is some platonic notion of the 
> > > ultimate meaning
> > > of a URI, how is that meaning conveyed to RDF (or 
> DAML+OIL, or OWL, or
> > > LBase, or any other formal system in the Web)?
> > 
> > You are now diverging to an entirely different issue.
> 
> I don't think so.  If there is no mechanism for conveying the 
> denotation to
> tools then what good is it?

Sorry, but that is a different issue. I.e.

Q: Who owns a URI        
A: The creator of the URI

Q: How does one determine who owns/created a URI
A: Depends on the URI scheme and other conventions

Q: How does one codify the denotation of a URI in a manner
   that can be understood by tools and applications
A: ???

The fact that there is no clear answer to the third question does
not mean that there are no answers to the first two.

Is the third question important? Sure. 

My own view, insofar as RDF systems are concerned, is that the
RDF system itself *cannot* capture the actual denotation of URIs.
URIs in RDF (and OWL) are atomic primitives. Their denotation is
defined externally to the system.

And for many denotations, I don't consider it possible to have a
formal means to express that denotation (without using yet another
layer of atomic primitives, which themselves must be defined in some
manner, etc. recursively, ad nauseum).

How http://example.com/foo/blargh is specified to denote a stale donut
on my desk is completely outside the machinery of RDF. It falls within
the domain of social conventions, not formal machinery.

> > The three key points of this thread are:
> > 
> > 1. URIs should have unambiguous, consistent, global, and 
> immutable denotation.
> > 2. Each URI has a specific owner, who has the right to say 
> what it denotes.
> > 3. Statements made by owner of a resource can be considered 
> to have special 
> >    sigificance/authority over statements made by 3rd parties.
> > 
> > How the denotation of a given URI is defined, or how the 
> semantics of the
> > resource denoted are defined, are outside the scope of this 
> particular
> > discussion.
> 
> I disagree entirely.  

Well, I've provided numerous arguments for why I see things the
way I do. You have offered little to no arguments against. Perhaps
you would like to outline in more detail why you think RDF cannot
work properly without having explicit formal mechanisms for actually
capturing the denotation of URIs. 

> If you can't turn your vision into 
> something that
> affects tools, then why should anyone care about it?

I would hardly consider it a "vision". Seems more like common sense to me.
And it's hardly "mine".

> > They're important issues in their own right, of course. Feel free to
> > start a separate thread to discuss them.
> 
> No thanks.  Theories of meaning in the Semantic Web should 
> connect to the
> formalisms of the semantic web.

Here's the formalism. URIs are atomic primitives of the SW. Their
denotation is defined externally to the machinery of the SW.

This is no different than e.g. syntactic primitives in a programming
language. They are not defined in terms of the language itself. They
are atomic. Their meaning is hard-coded into the compiler and other
tools operating on code.

Prove to me that you can create a formalism to capture the denotation
of http://example.com/foo/blarg to the donut on my desk, and I'll
rethink my view about URIs being atomic primitives in RDF.

And again, the issue of how to express denotations is completely
separate from the issues of ownership of URIs and who has the
authority to specify their denotation.

> > > > If I mint a URI and say it denotes the city of Paris, 
> France. And
> > > > you come along and use it to denote the city of Paris, 
> Mississippi,
> > > > then you are wrong and I am right, because it's *my* URI. 
> > > 
> > > How is it your URI?
> > 
> > Because I created it. Is that really so hard to understand?
> 
> Yes.  Even the notion of who creates a URI reference is 
> extremely murky.
> For example, who created the URI reference http://www.foo.ex/#a ?

I don't know. And if I don't know who the owner is, then I can't 
obtain any authoritative information about what it denotes and 
therefore I should be very wary of using it.

But the first place I'd start in trying to find out, would be the
agency which controls www.foo.ex (presuming, of course, that it is
a valid domain).

> > > > It's as
> > > > simple as that. 
> > > 
> > > This is not simple, it is, instead, extraordinarily complex.
> > 
> > No. I think you simply want it to be complex. Or perhaps are
> > not able to dissect a number of disjunct issues and address
> > each individually. The issue of URI ownership and denotation
> > is very simple.
> 
> So tell me who owns http://www.foo.ex/#a .
> Tell me what http://www.foo.ex/#a denotes.
> 
> Tell me who owns http://www.dccomics.com/#clarkkent .
> Tell me that http://www.dccomics.com/#clarkkent denotes.

Again, one would start with the agency controlling the domain.

As an aside, if there were semantic web enabled web servers at http://www.foo.ex
and http://www.dccomics.com which supported my proposed MGET method then one
could do an MGET on the URIs and possibly get back knowledge about the resource
regarding ownership, as well as information which may be sufficient to clarify
which resource is denoted by that URI.

So if I wanted to know what http://www.foo.ex/#a is, I could just do
MGET http://www.foo.ex/#a and examine the RDF description returned by 
the server.

Do I expect that the description returned is going to provide any kind
of complete and precise formal expression of the denotation itself? No.
Not such that a machine would necessarily be able to understand it. Might
it include human-understandable information which may be sufficient for
a human to understand what resource is denoted? Hopefully and probably.

> > > For example, suppose DC Comics mints a URI reference, 
> > > 	http://www.dccomics.com/#clarkkent
> > > what exactly does this denote?  
> > 
> > Whatever DC Comics *says* it denotes. They created it,
> > so they get to say what it means. Simple.
> 
> Not simple.  Suppose they don't say what it denotes.  

Er. Well, then what would be the point of minting the URI?

If they own the URI, but don't say what it denotes, then you
can't use it in RDF in *any* meaningful way. Any statement you
might make with it would be meaningless.

> Suppose 
> I want to
> point out problems with their use of the URI references.

How *could* they use it? If they use it, then they are clearly
presuming that it has some denotation.

You example is simply not rational.
  
> Suppose their
> entire world view doesn't make sense.

Then how is that a problem for RDF. RDF will not be able to solve
insanity in the world.

> > If that denotation doesn't work for you, then don't use it.
> 
> Then how can I communicate with DC Comics, if only to discuss 
> problems with
> their view of the world.

If the URI has no denotation, or if you don't know what the URI denotes, then you 
can't communicate about the resource denoted.

If you wish to communicate about the URI itself, you can reify it, such
as by using the uri: URI scheme. I.e.

   #Peter #doesNotUnderstandTheDenotationOf <uri:http://www.dccomics.com/#superman> .

And let's say you actually come up with some way to formulate the actual
denotation of URIs, by some lower level of atomic primitives below the
level of URIs. Then you could use RDF to express such denotations as

   <uri:http://www.dccomics.com/#superman> #denotes ... .

where '...' is however you manage to (yet at another level) denote the resource
which the URI denotes (though I really don't see the point).

> > > Can I use this as a synonym for
> > > 	http://www.dccomics.com/#superman
> > 
> > Probably not, since the names carry "perspective" in addition to
> > denotation of some entity. But you digress.
> 
> Not at all.  You were proposing that there is some fixed
> ``unambiguous, consistent, global, and immutable denotation'' 
> for a URI
> reference.  If so, then synonym issues are yes/no issues.  

It depends on your definition of synonym.

If synonymity only deals with equivalence of denotation, then I would
say that the two URIs in your example may be used interchangably.

If synonymity also includes aspects of perspective, then they cannot
be used interchangably.

Yes, this is an issue that needs to be clarified for RDF. But it has
nothing to do with who has the authority to specify the denotation of
those URIs.

Perhaps owl:sameIndividualAs could indicate equivalence of denotation,
but not necessarily free interchangability, whereas owl:sameAs would
indicate both equivalence of denotation as well as free interchangability?

But regardless of whether two URIs which denote the same resource are
or are not freely interchangable, that has nothing to do with who
owns the URI and who has the right to specify its denotation.

> Now you are
> adding in some notion of ``perspective'' to fix problems with 
> this rigid
> designation view of the denotation of URI references. 

There is no problem to fix. 

> I was simply
> pointing out that denotation is a complex issue, and that simplistic
> solutions quickly break down.

You are reading alot into my posts, presuming that solutions to
one problem are also solutions to another, which I have never
suggested is the case.

> > Again, you are diverging into yet another issue that is completely
> > disjunct from the issue being discussed.
> 
> I disagree.  You are proposing a solution for the denotation of URI
> references.  I am pointing out problems with various aspects of this
> solution.

No. I've never been talking about the machinery of how URIs denote
resources and how that denotation might be formalized. I've been talking 
about who gets to say what a URI denotes (however they might say it).

> > Whether or not two different names which denote the same entity can
> > be used interchangably, as they may reflect distinct "perspectives" 
> > of that entity (such as "Morning Star" and "Evening Star" 
> both denoting
> > the planet Venus) that has nothing whatsoever to do with whether a
> > given URI has ownership and whether the owner has the ultimate right
> > to say what it denotes.
> 
> Again I disagree.  

Perhaps you would like to offer more substantive arguments than simply
expressing your disagreement?

Why do you disagree? Exactly *how* does any issue of perspective
associated with the use of a URI have anything to do with the issue
of ownership of the URI or authority to specify its denotation?

> > Again, if you wish to explore other issues, feel free to start a
> > new thread.
> 
> No thanks.
> 
> > > > The owner of a URI gets to say what it denotes and
> > > > if you don't agree, then don't use that URI. Use of 
> someone elses
> > > > URI is an implicit agreement about what the owner says 
> it denotes
> > > > (leaving aside cases of misunderstanding, etc.)
> > > 
> > > So how then can I utilize URI references such as 
> > > 	http://www.whitehouse.gov/#43
> > > I may want to use this well-known URI as a common source of 
> > > URI references
> > > for the U. S. presidents, so that I can communicate with 
> other people.
> > > However, I, like Michael Moore, may disagree with the 
> denotation that
> > > www.whitehouse.gov gives to this particular URI reference.  
> > 
> > Tough. Too bad. If you don't agree with, or can't use the 
> authoritative
> > denotation, then you'll have to find some other names to use.
> > 
> > Actually, I don't see how you can "disagree" with what the creator
> > of a URI says it denotes, since you have no authority to 
> say otherwise.
> 
> In your view of denotation, I can't.  However, I don't agree 
> with your view.

Well, you've not provided any substantive arguments either against
my view or presented an alternative view. So I can hardly give any
meaningful consideration to your disagreement.

> > You may disagree with some statement made about the 
> *resource* denoted
> > by a give URI, but you don't have any basis for disagreeing with 
> > the denotation specified by the creator of the URI, as the 
> creator of
> > a URI has the sole right to say what it denotes.
> 
> Again, only in your view of the denotation of URI references.

I find that it is a fairly common view.

> > > If I have to
> > > use the denotation given by www.whitehouse.gov, then I have 
> > > no way of even
> > > expressing disagreement with that denotation.
> > 
> > Correct. If you use that URI, you implicitly agree with its 
> specified
> > denotation. If you don't want to talk about what that URI 
> is specified
> > to denote, then don't use that URI. Pretty simple really.
> 
> Well, sure, this is a consequence of your view of the 
> denotation of URI
> references.  I view this as a severe problem with your view, 
> and believe
> that a different view of the denotation of URI references is 
> needed for the
> Semantic Web.

Then SAY WHAT THAT DIFFERENT VIEW IS.

All you seem to be able to do is express disagreement with my view,
which is simply a waste of my time.

> > > > Likewise, if I have a URI that denotes a document that 
> I wrote and
> > > > of which I am the owner, and I make a statement that e.g. it has
> > > > 4293 characters of textual content in it and you say it has only
> > > > 1882 characters of textual content in it, then my 
> assertion bears
> > > > an authority that yours does not. True, it may very 
> well be that you
> > > > are correct and I might be incorrect, but that doesn't 
> in any way
> > > > change the fact that assertions about a resource made by the 
> > > > owner of the resource bear special authority over 
> assertions made
> > > > by third parties.
> > > 
> > > Huh?  How?  Why?  What good does this do?
> > 
> > Well, to take one simple practical example, perhaps a 
> manufacturer of
> > a product has published some information about that 
> product, and some
> > trade publication has also published similar information about that
> > product. Knowing who has said what may be very important in choosing
> > what information one wishes to trust over the other. It may be that
> > one trusts the trade publication more than the manufacturer. Or one
> > may be aware of common errors made by that publication and wishes to
> > let knowledge from the manufacturer take precidence in the case of
> > a disagreement.
> 
> You appear to have changed from a view that the ``owner'' is 
> always right,
> to one where the ``owner'' may be wrong.  

No. I haven't. Re-read what I've said.

The owner of a URI is *always* right about what it denotes.

The owner of a resource *may* be wrong about *statements* made about
the *resource* denoted *by* that URI.

> This is good, in my 
> view, because
> there are many cases where the ``owner'' has been wrong.  

But never about denotation. Never. (unless they're an idiot)

> > > > > Ironically, your claiming that there is such an authority is 
> > > > > an example 
> > > > > of a local ascription of meaning based on 
> idiosyncratic use ;-)
> > > > 
> > > > I don't see that. I think you should re-read my post. 
> Perhaps you
> > > > missed what I was saying...
> > > 
> > > I don't think so.  I think that Mile's comments are exactly 
> > > correct.  
> > 
> > Then it appears that you're both wrong ;-)
> 
> Oh, but the two sides are not equal here.  For you to win, 
> there has to be
> no effective dissent.  For Miles and I to win, all there has 
> to be is a
> multiplicity of opinions.  

Well, I have a feeling that you and Miles are in a very small minority
on this particular issue (specifically, who owns a URI and who gets to
say what it denotes).

> > > All
> > > that there is in your post is one person's feelings as to how URI
> > > references are to denote.  Any other person could have a 
> > > different view of
> > > how URI references are to denote, and that other view would 
> > > have just as
> > > much validity as your view.
> > 
> > Sorry, but I believe that my view is born out by the specs, 
> as outlined
> > above. I also belive that my view is the most predominant 
> view in the
> > real world, both for developers as well as common users.
> 
> What specs?  

RFC 2396

> The RDF Core Working Group voted, with no objection or
> abstention, to remove that section of the docment. 

That does not mean that the WG rejected the substance of
that content, only that it was not critical to the spec and
still required clarification and revision, which we did not
wish to allow impact the schedule.

Be careful about reading too much into that decision.

>  Your 
> view may be the
> most predominant view of developers and users, but that 
> doesn't mean that
> it works in all cases.

I've yet to see a single example from you or anyone else
demonstrating how it does not work, or is in any way invalid.

> > I also challenge both you and Miles to point to any 
> normative content
> > in any relevant spec which suggests that individuals can mint URIs
> > using naming authorities they have no ownership or rights 
> to, or that
> > the denotation of a URI specified by the creator of a URI can be 
> > questioned by any other party. Good luck.
> 
> I believe that such content does not exist.  However, I don't 
> see what that
> has to do with the issue at all.  

Well, you challenged *me* to point to such content! How then does
it matter for my view but not for yours (whatever that view is, since
you've not really stated what it is).

> First, I don't know of any normative
> content of any relevant spec that mentions ``the denotation of a URI
> [reference] specified by the creator of a URI [reference]''.  
> (In fact I
> don't know of any spec that mentions the ``creator of a URI 
> [reference]''.)

RFC 2396 specifies a 'naming authority' and IMO it is clear that the
naming authority is the agency which mints a URI for the express purpose
of naming a resource.

> Second, Miles' and my view doesn't need any such support.  We are not
> arguing for a restriction on how URI references get their 
> denotation, which
> would need some normative support, but instead are arguing 
> against your
> proposed restriction.

I believe I am simply echoing that which is stated (albeit implicitly)
in RFC 2396.

The editors of that publication are welcome to correct me.

> > > For example, here is a view that I happen to subscribe to
> > > 
> > > 	In any formal system, such as RDF, the denotation of a name
> > > 	(including URI references as a special case) is left 
> > > unspecified.
> > 
> > *In* RDF, yes, but not in the larger context of where and how that
> > formal system is used.
> 
> What is this larger context?  Where is it defined?
> (If you are arguing for some sense of ``intended meaning'', 
> then, sure,
> some notion of intended meaning is useful.)
> 
> > > 	Statements in the formal system, including RDF statements, serve
> > > 	only as constraints on that denotation.  
> > 
> > But not the *only* constraints on that denotation. It is 
> presumed (in
> > fact IMO required) that there be system-external constraints on the
> > denotations of the names (URIs) used as atomic elements of 
> that system.
> 
> Again, where does this come from and how does it impact RDF?

Er... it is the very foundation of how RDF works.

URIrefs are opaque, atomic primitives which denote resources. RDF does
not say how they denote resources. Only that, whenever a given URIref
is encountered, it consistently denotes the same resource.

> > RDF does not happen "in a vacuum". 
> 
> Oh certainly, but neither, in my opinion, does RDF *have* to 
> work (solely)
> in the ``atmosphere'' that you are promoting.

Well, I don't see how RDF could possibly work without treating
URIs as atomic primitives.

> > > Any agent (including
> > > 	people) choose to believe certain statements, and thus 
> > > every agent
> > > 	can potentially have a different view of the denotation of any
> > > 	particular name.
> > 
> > They *may*. But differing views in the *denotation* of URIs 
> represents
> > a breakdown in the system. RDF presumes (even if it can't garuntee)
> > that URIs have globaly consistent, unambiguous, and 
> immutable denotation.
> 
> Here is were we differ.  I believe that forcing a too-rigid 
> view of the
> denotation of URI references will cause a breakdown in the system.

Then I don't consider your view to be either rational or reasonable.

> Further, I don't believe that *RDF* makes any presumption on 
> the denotation
> of URI references.   

Eh? What? And precisely where do you get that?

> > RDF is *not* like natural language. RDF is intended to be much more
> > precise, as are all formal languages, while still 
> tolerating a certain
> > degree of noise. Ambiguity and conflicting statements, even 
> if tolerable
> > to a certain degree, are nonetheless undesirable and 
> detrimental to the
> > optimal performance of that system, and therefore should be 
> minimized
> > as much as possible.
> 
> Well my view is that ambiguity and conflicting statements are 
> unavoidable,
> and, moreover, necessary to the functioning of the Semantic Web, and,
> therefore, any regulations to minimize them should be avoided 
> as much as
> possible. 

Well, I certainly hope your view remains a very, very small minority
on the SW.

The *ability* to operate gracefully in the presence of *undesireable*
but *unavoidable* ambiguity and disagreement will be a key feature of
SW agents. But ambiguity and disagreement are hardly *requirements* for
the functioning of the SW, and are IMO always detrimental.

> > > For contrast here is another view, that might be closer 
> to your view
> > > 
> > > 	There is some ultimate, timeless reality.  The 
> > > denotation of every
> > > 	possible name is fixed and unchangeable in this reality.  
> > 
> > Or rather, 
> > 
> >    There is a formal system for which the names in that system are
> >    presumed to have unambiguous, consistent, immutable 
> interpretation.
> > 
> > I don't see how the semantic web can offer any utility if it doesn't
> > correspond to such a formal system.
> 
> Well, I believe that if the Semantic Web does correspond to 
> such a formal
> system then its utility will be severely limited.

Well, I guess time will tell which of us is right.

> > > This second view appears to be very nice, but there are quite 
> > > a number of
> > > problems in it, including how to provide a denotation of
> > > 	http://www.whitehouse.gov/#46
> > > and
> > > 	http://www.dccomics.com/#clarkkent
> > 
> > I see no problems with the denotation of these URIs. They 
> denote precisely
> > what the creators of those URIs say they denote. If you 
> don't want to 
> > talk about the particular resources the owners say they 
> denote, then don't
> > use those URIs. It's as simple as that. You have *no* 
> authority or basis
> > to disagree with the denotation specified by the creator of 
> a URI. Tough.
> 
> Well, then I guess I won't play in your semantic web.  However, don't
> expect me to stop arguing for different views of the Semantic Web.

Fair enough.

Though be forwarned against any abuse of my URIs which undermine their
utility by introducing ambiguity based on disagreement with what I
say they denote, as I will guard their integrity agressively and
show you first hand who has the authority to specify their denotation.

;-)

> > > as well as how to deal with agents whose connection to 
> this ultimate
> > > reality is incomplete or incorrect.
> > 
> > This is yet another issue, disjunct with the issue being 
> discussed. Feel
> > free to start another thread to explore it.
> 
> Again, I view this as part of the same issue.  In particular, 
> what happens
> if the agent behind www.whitehouse.gov has an incomplete or incorrect
> connection to reality?  Your view would cut off communication 
> between this
> agent and other agents that have a better connection to reality.

Eh? Connection to reality? Sorry, I don't have any idea what you
are saying here.

Patrick



> > Patrick
> > 
> > --
> > Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, 
> patrick.stickler@nokia.com
> 
> Peter F. Patel-Schneider
> Bell Labs Research
> Lucent Technologies
> 
> 
Received on Thursday, 3 April 2003 02:14:21 GMT

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