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Re: Issue-57

From: Xiaoshu Wang <xiao@renci.org>
Date: Thu, 23 Jun 2011 15:08:20 +0000
To: Jonathan Rees <jar@creativecommons.org>
CC: Alan Ruttenberg <alanruttenberg@gmail.com>, Tim Berners-Lee <timbl@w3.org>, David Booth <david@dbooth.org>, Jeni Tennison <jeni@jenitennison.com>, "www-tag@w3.org List" <www-tag@w3.org>
Message-ID: <CA28B58C.10F80%xiao@renci.org>

On 6/22/11 8:06 PM, "Jonathan Rees" <jar@creativecommons.org> wrote:

>On Thu, Jun 16, 2011 at 7:35 PM, Xiaoshu Wang <xiao@renci.org> wrote:
>> For me, I don't care because if there is no ontology that classify
>> everything in the world into IR and if there is no reasoner that
>>implements
>> code to check every URI's response code and triggers subsequence
>>inference,
>> following httpRange-14 (even if I can) is simply a waste of time.
>>Hence, I
>> doubt I will ever do it. But for those who cares, 2xx code is cheaper
>>than
>> 303.
>> Xiaoshu Wang
>
>The reason for the httpRange-14 rule is that it lets us write metadata
>for things on the web in a direct way, and be understood.

http://example.com/xiaoshuwang is a Person.

Assuming the URI respond with 200. What is not 'indirect' and what cannot
be understood?

>The
>inference rule you are looking for is: If U is a dereferenceable
>absolute URI, and M(<U>) for some metadata M, and a retrieval of U
>yields a representation Z, then M(Z). E.g. if an information resource
>has dc:title "Little mouse", then its associated representations do,
>too. Conversely, if M(Z) consistently for Z retrieved from U, then
>M(<U>).

I don't quite understand it. But whatever it is: do you think any reasoner
will implement the necessary code to check how every URIs in an RDF doc
get responded?

>
>I agree with you: if nothing important follows about <U> from
>retrievals of U, then there is absolutely no reason to assume anything
>about the relation between <U> and U. But metadata is important and it
>does follow. Maybe my logic is a bit too simplistic, but I think
>metadata is the previously unarticulated justification for the rule.
>And it is very consequential - statements of license and authorship
>can have quite serious ramifications. There is no metaphysics
>involved.

What is metadata (or for that matter, what is data)? Excuse for me picking
bones from egg. But I do get confused with the word metadata, especially
in RDF world. Given an RDF doc, can you tell part of them is metadata and
the other not?


>
>The rule is misstated and that has confused everyone; it seems to be
>about an "information resource" type distinction but it makes a whole
>lot more sense if it is about the relation between a URI and the
>particular metadata subject (information resource, document, whatever)
>*served from that URI* - not to just any old information resource, but
>that particular one. I think the creators of the resolution took this
>as a given.
>
>I've written this up here:   http://www.w3.org/2001/tag/awwsw/ir/20110517/
>
>Now, if you have a better way to write this kind of metadata, then you
>don't need the httpRange-14 rule, but we absolutely need *some* way to
>write metadata and I have yet to see anyone propose a better one. All
>the alternatives I've come up with are very ugly as they involve an
>occurrence of the URI as a string.
>
>You ask what we gain from this; it's the ability to talk easily,
>naturally, and consequentially about what's on the web. Practically
>every rdfs:seeAlso, owl:imports, foaf:homePage, dc:creator,
>xhtml:license depends on this convention. There's a ton of metadata
>out there, often doing its job inconspicuously. People usually follow
>the httpRange-14 rule without even thinking about it. That's why it
>has so few champions. Without the rule, there is huge FUD about every
>use of all of these properties, very serious ambiguity when a page
>could be about a page, and we may as well just stop writing metadata
>the way we do now. This is the direction we're headed if we can't get
>stronger agreement.

If I receive a message saying:

U1 a :Person.

I don't see anything difficult to understand it. And if I try to
dereference U1, I should expect something about a person. If not, I would
think that the person who authorized the U1's response is sloppy, or has
mal-intension. Whether I got back 200 or not doesn't affect my
understanding at all.

Of course, this is not what you have in mind. You were thinking the case
such as:

U1 a :Person.
U1 foaf:homePage U1.

People's first reaction is: this is wrong. But, what if this is the
author's intention. That is: he is using U1 to reference the entity that
is both a Person and a Web Page. (Please do not say that such a thing does
not exist because then you must define the word 'existence'. For this, I
recommend reading Quine's "On What There is".)

I am not recommending people to practice like this. But my point is: the
Web is about communication. We might not believe other's theory, but who
are we to tell them "to shut up"?

If the author of U1 wants to describe the webpage of U1 without raising
unnecessary confusion, he can still do it with

U1 a :Person.
<__:webpage> ex:webpageof U1.
<__:webpage> foaf:homePage U1.
<__:webpage> dc:title "blah, blah".

Is it difficult? I don't think so. Is it clear? I think so.

Please note, I am not suggesting replacing 303 use this approach. If
people don't feel comfortable of b-node, then can by all means use 303.
The point that I want to stress is: the ambiguity problem resides in how
we describe things. It has nothing to do with HTTP protocol.
 

>
>(And by the way a lot of people think 303 means not-an-IR. There is no
>justification for this idea and it is false in practice. A good
>example is the 303 responses served from dx.doi.org, where the URIs
>name documents without any commitment as to whether they are or aren't
>on the web.)
>
>I'm not trying to persuade you it's a good design (although if you
>think otherwise I'd like to see what you'd substitute as a metadata
>notation), I'm just trying to get you to stop saying the rule is
>inconsequential or without serious purpose.

The original purpose of httpRange-14, I guess, is to avoid ambiguity. But
ambiguity can only be cleared with more ontological assertions.
httpRange-14 has raised more confusion/debate. Except transferring
ambiguity to a different term, what problem it has solved?

Xiaoshu
Received on Thursday, 23 June 2011 15:08:54 GMT

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