Re: Terminology (was Re: article on URIs, is this material that can be used by the)

Like Henry Thompson, I've never felt that the English word 
"representation" suggests either completeness or full fidelity.  Indeed, 
had the history of the Web been a bit different, I personally would have 
had no objection to allowing retrieval of "representations" even of 
tangible objects that are not what we now call information resources. 
Although an information resource >can< be represented with full fidelity 
in a message, we clearly allow for less than full representations anyway, 
even with a 200.  For example, I think it's OK to conneg between image/gif 
and image/jpeg for the same photo, yet almost surely at its native 
resolution GIF will preserve detail that jpeg doesn't, but when zooming 
most viewers would feel that jpeg remains truer to what is (presumably) 
the photograph itself.  We also allow for foreign language translations of 
text information resources, even though those almost surely lose some 
nuance.  So, even in the Web as deployed today, is precedent for 
representations of information resources being incomplete or otherwise 
imperfect.  In principle, I would think we could have representations of 
concrete objections as well.

However, I have come to believe that:

* The distinction between information resources and non-information 
resources is a useful one.

* Having HTTP GET indicate in the results of an interaction whether what 
has been contacted is in fact an information resource, and thus whether 
the representation stands in the sort of relationship to the resource that 
we expect for information resources (which >can< by definition be 
faithfully sent in message), is useful.

* We should respect the precedent that's been established for signalling 
this, which is to use HTTP status code 200.

So, I would have not have had objections in principle if the Web had done 
this differently, but I think the path we're on is OK.  200 means 
information resource.  We now have to establish best practice in the case 
that it's a non-info resource,  which is what the TAG is lately 


Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142

Received on Tuesday, 26 June 2007 14:47:14 UTC