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Re: ISSUE-148: IRIs do *not* always denote the same resource

From: Eric Prud'hommeaux <eric@w3.org>
Date: Fri, 20 Dec 2013 07:40:57 -0500
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Guus Schreiber <guus.schreiber@vu.nl>, RDF Working Group WG <public-rdf-wg@w3.org>
Message-ID: <20131220124054.GA20233@w3.org>
* Richard Cyganiak <richard@cyganiak.de> [2013-12-19 23:17+0000]
> Guus,
> 
> The WG has extensively discussed the issue with David. The WG has then reached consensus on ISSUE-148, and resolved to close it.
> 
> The WG also has already resolved to ship the spec in its current state.
> 
> In the spirit of respecting the process and respecting the hard work that WG members are putting into reaching consensus, I ask that this not be re-opened.

Can we punt it to the TAG on the basis that it has no more to do with
RDF than it does with any XML language (e.g. SOAP, XML Schema, ...) or
any other language using IRIs as identifiers?


> I could write up the technical and editorial rationale against the change, but the process should protect me from having to do that *again*.
> 
> Best,
> Richard
> 
> 
> 
> On 19 Dec 2013, at 22:17, Guus Schreiber <guus.schreiber@vu.nl> wrote:
> 
> > All,
> > 
> > You probably saw the message from David Booth about ISSUE-148 on the comments list.  In the W3C spirit of doing the ultimate for consensus I created a straw poll to get  your opinions on the amendment he proposes. Based on the outcome the chairs will make a suggestion  whether or not further action is called for.
> > 
> > The straw poll is here (and open until the end of the year):
> > 
> >    https://www.w3.org/2002/09/wbs/46168/issue-148/
> > 
> > Enjoy your Xmas break.
> > Guus
> > 
> > 
> > 
> > -------- Original Message --------
> > Subject: Re: ISSUE-148: IRIs do *not* always denote the same resource
> > Resent-Date: Thu, 19 Dec 2013 20:26:55 +0000
> > Resent-From: <public-rdf-comments@w3.org>
> > Date: Thu, 19 Dec 2013 15:26:22 -0500
> > From: David Booth <david@dbooth.org>
> > To: Guus Schreiber <schreiber.guus@gmail.com>
> > CC: Public RDF comments list <public-rdf-comments@w3.org>
> > 
> > On 12/18/2013 09:33 PM, David Booth wrote:
> >> On 12/18/2013 05:47 PM, Guus Schreiber wrote:
> >>> David,
> >>> 
> >>> The RDF WG resolved today [1] ISSUE-148:
> >>> 
> >> > Resolve ISSUE-148 by changing the "IRIs have global scope"
> >> > bullet point in section 1.3 in Concepts to "By design,
> >> > IRIs have global scope. Thus, two different appearances
> >> > of an IRI denote the same resource. Violating
> >> > this principle constitutes an IRI collision
> >> > [WEBARCH]." http://www.w3.org/TR/webarch/#URI-collision
> >> >
> >> > We very much hope you can live with this outcome. It might
> >> > not be exactly what you wanted, but I hope it is at least
> >> > very close to it.
> >> 
> >> Indeed, this is close, but it still does not address my concern,
> >> because it still says "two different appearances of an IRI
> >> denote the same resource" as though that is always true, in
> >> spite of fact that the next sentence acknowledges that this
> >> can be violated (though it gives no clue about how).
> >> 
> >> I gather that someone didn't like the word "should" or the
> >> phrase "is intended to" that were proposed earlier.   As a
> >> compromise, how about inserting "RDF assumes that":
> >> 
> >>   "By design, IRIs have global scope. Thus, RDF assumes
> >>   that two different appearances of an IRI denote the same
> >>   resource. Violating this principle constitutes an IRI
> >>   collision [WEBARCH]."
> >>   http://www.w3.org/TR/webarch/#URI-collision
> >> 
> >> David
> > 
> > P.S. According to the meeting minutes,
> > http://www.w3.org/2013/12/18-rdf-wg-minutes.html#item05
> > the WG **did not even consider** any wordings that would have fully
> > addressed the concern that caused me to raise this issue.  The only two
> > options that were considered were *identical* in still having the
> > problem described above.
> > 
> > I know it isn't easy to craft verbiage that is acceptable to many
> > different parties with different perspectives, and I have offered to
> > help do that.  But the way the working group has handled this --
> > simultaneously prohibiting discussion on the public-rdf-comments list
> > while also prohibiting non-member subscription to the working group
> > discussion list -- has left me only an extremely blunt instrument for
> > communicating with the working group.  In essence, all I can do is raise
> > a formal objection.  And friends, that's rather broken.  It sure ain't
> > very efficient.
> > 
> > This is the time to get this fixed.  We should not go another 5 years
> > with wrong/misleading statements about the uniqueness of IRI reference,
> > leading new RDF users down a garden path only to be surprised and
> > disappointed later when merged graphs don't work as expected.  One might
> > assume that, because this text is a non-normative introduction, it isn't
> > very important.  But it *is* important because it affects how the reader
> > thinks about the whole specification.  Readers need to know that URI
> > collisions can happen **even with RDF that is 100% compliant with the
> > RDF specification**.
> > 
> > The currently adopted verbiage *almost* addresses my concern, because it
> > acknowledges that the principle of unique URI reference *can* be
> > violated.  But alas, as currently phrased, readers are likely to assume
> > that such violations are violations of the RDF specifications, rather
> > than violations of a higher level architectural objective.  Readers need
> > to know that RDF makes the *assumption* of unique URI reference, and
> > hence if this assumption is violated, there may be problems due to URI
> > collision.
> > 
> > I have spent a *lot* of time over the past several years -- probably
> > *thousands* of hours cumulatively -- trying to get to the bottom of the
> > resource identity issue.  In fact, I may have spent more time on this
> > issue than all other members of the RDF working group *combined*,
> > excluding Pat Hayes!  But that is mere idle speculation.  The point is
> > that although this may seem like a trivial issue to some, it is
> > important to me, as to my mind it ultimately underlies nearly
> > *everything* we do in the Semantic Web that we're trying to build.
> > 
> > I have done my best to work as efficiently as possible with the RDF
> > working group -- moving lengthy discussions to other lists, trying hard
> > to reach common understanding with other individuals before proposing
> > fixes that might reach consensus, and offering to help craft acceptable
> > wording -- but as explained above, the constraints imposed by the
> > working group have made the process frustratingly difficult and awkward.
> > 
> > So, I guess I will rephrase my suggestion above.  Would anyone strongly
> > *object* to inserting "RDF assumes that" in the currently adopted bullet
> > phrasing, as described above?  If so, why?
> > 
> > Thanks,
> > David
> > 
> > 
> > 
> > 
> > 
> 
> 

-- 
-ericP

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Received on Friday, 20 December 2013 12:41:31 UTC

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