On 11/6/10 4:42 PM, David Booth wrote:
httpRange-14 requires that a URI with a 200 response MUST be an IR;
^^^^^^^
Not quite. The httpRange-14 decision says that the resource *is* an IR:
http://lists.w3.org/Archives/Public/www-tag/2005Jun/0039
a URI with a 303 MAY be a NIR.
Ian is (effectively) suggesting that a URI with a 200 response MAY
be an IR, in the sense that it is defeasibly taken to be an IR,
unless this is contradicted by a self-referring statement within
the RDF obtained from the URI.
To be clear, Ian's toucan URI *does* identify an information resource,
whether or not it *also* identifies a toucan:
$ curl -I 'http://iandavis.com/2010/303/toucan'
HTTP/1.1 200 OK
Date: Sat, 06 Nov 2010 20:05:57 GMT
Server: Apache/2.2.8 (Ubuntu) DAV/2 SVN/1.4.6 PHP/5.2.4-2ubuntu5.10
with Suhosin-Patch mod_wsgi/1.3 Python/2.5.2
Content-Location: toucan.rdf
Vary: negotiate
TCN: choice
Last-Modified: Fri, 05 Nov 2010 09:24:27 GMT
ETag: "264186-403-4944ad745a8c0;4944ad754eb00"
Accept-Ranges: bytes
Content-Length: 1027
Content-Type: application/rdf+xml; qs=0.9
Thus, Ian has created an ambiguity by returning a 200 response. There
is nothing fundamentally wrong with this, as ambiguity of resource
identity is inescapable anyway, and we just have to learn to deal with
it. However, for those applications that need to distinguish between
the toucan and its web page, Ian is effectively suggesting the
*heuristic* that if the content served in the 200 response says that the
URI identifies a toucan, then the app should ignore the fact that the
URI also identifies a web page, and treat the URI as though it *only*
identifies the toucan.
David,
What about this:
1. a 200 OK response infers that a URI is a URL (an Address) since its
an indication of that a Resource has been located
2. existence of a self-describing resource discovered via
"Content-Location" header value (e.g. touscan.rdf) can result in an
override if the data states that the URI is a Name.
I really think we have to emphasize the "Address" and "Name" aspects of
a generic URI, at every opportunity. Personally, I think it helps
understand what the actual ambiguity is about.
This option showcases good RDF dog-fooding, especially as the Semantic
Web Project has always been about self-describing data :-)
--
Regards,
Kingsley Idehen
President& CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen
