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Re: AWWSW vs. httpRange-14

From: Jonathan Rees <jar@creativecommons.org>
Date: Fri, 11 Feb 2011 15:06:20 -0500
Message-ID: <AANLkTikLGcTRqCRWFptcVymnw5WiFhG3WR3JL5z2u8jE@mail.gmail.com>
To: David Booth <david@dbooth.org>
Cc: AWWSW TF <public-awwsw@w3.org>
On Fri, Feb 11, 2011 at 2:07 PM, David Booth <david@dbooth.org> wrote:
> Hi Jonathan,
>
> I want to see if I am properly understanding what you mean, so I'll
> reflect back a bit for you to verify or correct.
>
> On Fri, 2011-02-11 at 10:38 -0500, Jonathan Rees wrote:
>> In my current view there are two issues:
>>
>> 1. What notation do we use to write a reference to an 'information resource'?
>
> Do you mean an *explicit* reference, such as <http://example/#foo> in
> the following RDF statement:
>
>  <http://example/#foo> a :InformationResource .
>
> Or do you mean an *implicit* reference, by virtue of the fact that an
> HTTP GET on that URI yielded a 200 status?
>
>  <http://example/bar> :createdOn "2009-12-31"^^xsd:date .
>
> where a GET on http://example/bar yields a 200 response with a document.
>
> Or do you mean both?  Or something else?

What I mean is, that currently when someone wants to say that a
document has a title or a license, they use the document's URI (the
URI from which they GET the document or its "representation") as the
subject of an RDF statement.

I have interpreted the httpRange-14 resolution as reflecting a
suggestion that people use these URIs in this way (and not in some
other way). This has been widely assumed, e.g. FOAF and CC REL.

This practice has been questioned, so we have to consider other
options in order to do an honest appraisal of the alternatives.

Webarch, RFCs 3986 and 2616, and the httpRange-14 resolution seem to
be fairly explicit, but by your definition these references are
implicit.

>> 2. What does such a reference mean, such that it can be used to good
>> effect in various kinds of statements (eg. Dublin Core, FOAF, CC REL)?
>
> Do mean: "What other RDF assertions should be used if a URI is used in
> an RDF statement?"?

By "mean" here I mean according to current and/or future community
consensus. Qualifying RDF statements isn't what everyone does now, and
it may or may not be part of a future consensus; I don't know how it's
going to turn out.

> If so, this sounds right up the ally of "Statement author responsibility
> 3" and "Consumer responsibility 5" in
> http://dbooth.org/2009/lifecycle/

An agreement with these rules would preclude any referential use of
these URIs, since nobody would know the meaning of the 'core
assertions' they would be agreeing to. Or, if there were no such
assertions, then nobody would use these URIs since statements using
them wouldn't convey anything at all. Adoption would say that CC would
have to retool since none of its license assertions have any meaning.
So it sounds like you're in the don't-be-unclear camp with Alan,
Harry, and Larry. Am I the only one here trying to explain and
maintain the value of the current investment in metadata?

I would think one way to go would be to explain why these metadata
assertions work socially, and under what limitations, and then try to
build consensus around whatever it is we learn. If not then we'll have
to retract every bit of advice ever given about writing metadata in
RDF.

Jonathan

>> Clearly these interact, but pretend for a minute that they don't.
>>
>> #1 is related to Harry's complaint that # and 303 are too hard; he
>> doesn't like it that we use dereferenceable URIs as references to
>> information resources, because he thinks those URIs can be put to
>> better use.  (IIUC.)
>>
>> #2 was the complaint that created AWWSW: If I *do* use a term (URI or
>> anything else) referring to an "information resource" in a proposition
>> (metadata), what do I mean, even if the webarch is assumed; and might
>> we either record or set expectations for their use.
>>
>> The TAG was convinced this week that an issue needs to be opened for
>> #1, and I will be moving that forward.
>>
>> It was already convinced #2 was a question, and that's how AWWSW was
>> established.
>>
>> I think that Harry and Alan (and Larry Masinter) are saying something
>> similar, which is: If it matters whether your meaning is clear, then
>> IR references do not stand on their own, as they are inherently
>> unclear.  To obtain interoperability, you have to stop talking about
>> 'the information resource at a URI' entirely, regardless of how you
>> refer to them. IR is a lost cause.
>>
>> This cuts both ways. If you want to be clear that you mean to use an
>> http: URI to refer to something described in the accessed document,
>> you need to write some statements to that effect.
>
> Such as by owl:imports?
>
>> (This is clearly
>> even harder than using # or 303.) If you want to be clear that you
>> want it to mean the document, you also need to say something.  (So
>> Creative Commons and FOAF would need to retool.)
>>
>> In this pessimistic view it's only if you don't care about being clear
>> that http: URIs serve as references.
>>
>> In either case RDF graph merging (i.e. interoperability) is defeated
>> since to merge a graph using a URI in one way with a graph using a URI
>> in the other way either one or the other graph would need
>> alpha-conversion, a rather nasty procedure.
>
> Pointer to alpha-conversion please?
>
> thanks,
> David
>
>>
>> (There is a somewhat different story in the OWL context but I think
>> much of this still applies.)
>>
>> The way to get interoperability is to stop using http: URIs (or at
>> least hashless ones) for reference entirely. In this case we would
>> still need a 'web semantics' to provide a vocabulary for talking about
>> the documents that we find on the web, and perhaps relating them to
>> the things they describe.  So the AWWSW project is in a sense
>> independent of the notational question of what RDF terms we use to
>> refer to IRs or documents.
>>
>> I hope it's clear I haven't completely given up on this as Harry and
>> Alan have. However I do consider despair an option.
>>
>> By the way I had forgotten about TAG Issue 39
>> http://www.w3.org/2001/tag/group/track/issues/39 , which seems to be
>> forgotten and forlorn. I'm not sure if it would be appropriate to
>> track #1 and/or #2 under this issue; I sort of disagree with the
>> formulation of the problem and I'm not sure AWWSW is a part of this.
>> I'd be interested in hearing others' thoughts on the relation of our
>> work to issue 39.
>>
>> Jonathan
>>
>>
>>
>
>
>
Received on Friday, 11 February 2011 20:06:54 GMT

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