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Re: owl:sameAs use/misuse/abuse Re: homonym URIs

From: Dan Brickley <danbri@danbri.org>
Date: Wed, 27 Jun 2007 02:11:12 +0200
Message-ID: <4681AB20.1020904@danbri.org>
To: Tim Berners-Lee <timbl@w3.org>
CC: John Black <JohnBlack@kashori.com>, Richard Cyganiak <richard@cyganiak.de>, Jacek Kopecky <jacek.kopecky@deri.org>, Bernard Vatant <bernard.vatant@mondeca.com>, semantic-web@w3.org

Tim Berners-Lee wrote:
> 
> On 2007-06 -25, at 11:00, John Black wrote:
>> [...] But surely a URI is an information resource in the same way that 
>> a blog post is and so it can be represented by a web page the same way 
>> a blog post is represented by the web page you get through HTTP.
>>
>> Now my FOAF URI is this http://kashori.com/JohnBlack/foaf.rdf#jpb. As 
>> a URI, it is an information resource, namely a string of characters 
>> conforming to rfc3986.
> 
> Well, that is not how Information Resource is used in the web 
> Architecture.  An Information Resource conveys information, and in the 
> web architecture it can severl representations, but any one of them must 
> have a content-type (and possibly other metadata) as well as a string 
> of  bits.

I'd really like to see a pretty formal spec for "InformationResource". 
There are plenty of corner cases to flush out.

On my system, the URI file:///Users/danbri/.cpan/sources/MIRRORED.BY 
deref'd in Firefox gives me a textual document containing metadata about 
the Perl CPAN system. Is that URI the name of an information resource?

How about:

data:,A%20brief%20note

(no obvious way to get content-type, unless the data: URI scheme defines 
a default)

data:image/gif;base64,R0lGODdhMAAwAPAAAAAAAP///ywAAAAAMAAwAAAC8IyPqcvt3wCcDkiLc7C0qwyGHhSWpjQu5yqmCYsapyuvUUlvONmOZtfzgFzByTB10QgxOR0TqBQejhRNzOfkVJ+5YiUqrXF5Y5lKh/DeuNcP5yLWGsEbtLiOSpa/TPg7JpJHxyendzWTBfX0cxOnKPjgBzi4diinWGdkF8kjdfnycQZXZeYGejmJlZeGl9i2icVqaNVailT6F5iJ90m6mvuTS4OK05M0vDk0Q4XUtwvKOzrcd3iq9uisF81M1OIcR7lEewwcLp7tuNNkM3uNna3F2JQFo97Vriy/Xl4/f1cf5VWzXyym7PHhhx4dbgYKAAA

(more obvious content-type in there ... but its scheme specific...)

> Oh, Yes you do, as a literal string is not an information resource.

It's not? http://www.w3.org/TR/webarch/#id-resources seems a little more 
permissive. The requirement that "information resources" representations 
must come with a content-type seems a bit strict. If something doesn't 
tell you the content-type, does the resource stop being informational?

Dan
Received on Wednesday, 27 June 2007 00:11:22 UTC

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