Re: JAR's exploration of TimBL's notion of information resource

Sort of an aside, and I hope at worst not disruptive...

Jonathan Rees wrote:

> Hardly!  If for U the server responds with a wa-representation X that is
> *not* a wa-representation of the resource in question G, then it is 
*not*
> consistent with G at U. That is, some *other* resource might be
> served by S at U.

Long ago, when I first joined the TAG, I attempted to write a working 
draft on the relationship between URI schemes and protocols.  There were 
several drafts, each of which led to a lot of difficult debate, leading me 
to conclude that, at the time anyway, I knew too little about the Web to 
write such a finding.  So, I put it aside.   The quote above does remind 
me of something I tried in the last draft that I wrote.  I made an attempt 
to set out rules that applied to the responsibilities of servers, clients, 
etc., one of which was [1]:

"4.1.2 R2. Serve faithfully

"A server MUST serve resources faithfully. Regardless of the protocol 
used, the server is responsible for ensuring that the correct resource is 
accessed, that operations are correctly implemented according to the 
specifications for the protocol, and thus that the correct resource state 
is either retrieved or updated. In the example above, serving the ftp 
resource using HTTP is appropriate only insofar as the operations of HTTP 
can in good faith be supported on that particular resource. The server 
must have access to the state of the resource, using an FTP gateway or by 
some other means, and it must ensure that all supported HTTP operations 
properly retrieve or update the state of the resource.

"For many combinations of scheme name and protocol, such faithful serving 
is by definition impossible. For example, there is probably no faithful 
manipulation of a mailto: resource possible using the FTP protocol. Thus, 
this rule prohibits use of many combinations of schemes and protocols."

As I recall, this formulation did not meet with a lot of support from the 
members then on the TAG, but I find that I do still think about things in 
these terms.  Maybe or maybe not some of the other "rules" will eventually 
prove close to the mark.  Anyway, the proposed "serve faithfully" rule 
seems very much complementatary to the assumption embodied in the quote 
from Jonathan.   Perhaps thinking about this will suggest some useful 
approaches to the G/U/IR questions.

Noah

[1] http://www.w3.org/2001/tag/doc/SchemeProtocols.html#serverGoodFaith

--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
--------------------------------------

Received on Tuesday, 26 May 2009 16:37:58 UTC