xml-dev - RE: URI concerns continue

["Bullard, Claude L (Len)" <clbullar@ingr.com>]

All forms of human communication require consent.  So, 
shaky ground is the best we get.

Your post is a fair condensation of the original discussions 
on URL/URN/URIs as namespace identifiers.  Essentially, 
if you conflate identity, name, and location, you face 
some problems and you have others if you don't:

1.  Record of authority:  who owns it, who controls 
it, how is it known and controlled; can this be cited 
and tested/proved

2.  Resolution:  is a name a location identifier and can it 
be resolved.  Identity may have a mathematical 
definition but it is for the most part, philosophical 
in implementation.  That is why I regard those 
who think they can always discriminate rhetoric from logic 
and assert the superiority of logic with suspicion.  
Again, what is the age of the dead man? Answer:  it 
is not a fact.  It is derived and without stating 
the semantic of the derivation, arguable.  This is 
the central problem of contract/consent based systems: semantics. 
It is the central dilemma of the so-called semantic web.

3.  Is there a means to determine a superstitious 
assertion?  In behavioral science, this is a behavior 
acquired as a result of an observation leading to a 
false association of cause and effect, thtat is,
one that is only reliable some of the time and 
then only coincidentally.  See B.F. Skinner.  This 
is a central issue of the reliability numbers in logistics 
analysis.

Essentially, URI/URN/URL are simply system specific 
aggreements about these problems and are based on a 
working philosophy (say, implementable) about how 
things will be named, found, and discriminated on a 
system named the World Wide Web.  The only guarantees 
are behavioral:  repeatable results at some satisfactory 
level of sustained repetition (eg, nothing can guarantee  
the network is always up or available).

The question then is should such a system specific 
naming philosophy become part of the information 
which that system handles?   The SGML answer was 
no.  Public identifiers (contractual and yes similar 
to ISBNs) are there for formal naming.  System identifiers 
are there for resolving a location to a thing which the 
FPI may or may not name (not required in the instance). 
There are few guarantees in the FPI; it is a convenience 
for a separate process of contract based communication. 
System identifiers are guaranteed; must resolve.  A third 
entity, the catalog, was created to enable a system 
implementor to agree to a means to tie these together 
for authoritative resolutions.
 
The WWW answer has been we should be able to resolve 
or not resolve the location by a name in which the 
system implementation is the guarantor insofar as 
it can be guaranteed to have a unique identity.  This 
simply avoids the catalog but it makes it difficult 
in all cases to determine the correct behavior.

There is room for both approaches in the identification 
of the schema or DTD.  In the namespace of an aggregate, 
we don't seem to be in any more or less trouble unless 
we attempt to resolve the value of xmlns.  Heretofore, 
that was considered outside the scope of the namespace 
spec, or so we were told until implementors began to 
resolve them simply because with a protocol identifier, 
they could in some cases.   On the other hand, that isn't 
guaranteed.

Len Bullard
Intergraph Public Safety
clbullar@ingr.com
http://fly.hiwaay.net/~cbullard/lensongs.ram

Ekam sat.h, Vipraah bahudhaa vadanti.
Daamyata. Datta. Dayadhvam.h


-----Original Message-----
From: Lee Anne Phillips [mailto:leeanne@leeanne.com]
Sent: Tuesday, July 11, 2000 9:44 AM
To: XML-Dev Mailing list
Subject: Re: URI concerns continue


I agree the URI's are built on quicksand for the most part, once you leave 
the shaky ground provided by URLs, which have their own problems. The whole 
concept of "authorities" presumes an exactitude in the world that simply 
doesn't exist in any real sense. Even URL's can be (and have been) 
subverted. The authority of URL's depends entirely on the goodwill and 
skill of all (or almost all) participants in the DNS scheme of things.