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Re: [ontolog-forum] {Disarmed} Re: OWL and lack of identifiers

To: Pat Hayes <phayes@xxxxxxx>
Cc: "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Ed Barkmeyer <edbark@xxxxxxxx>
Date: Mon, 16 Apr 2007 17:06:37 -0400
Message-id: <4623E55D.5050208@xxxxxxxx>
Since we are having such a good time with this...    (01)

First, thanks, Pat.  I am happy that someone who is connected to the process 
has added some clarification as to the current state of standards activities 
in this area.  The debate is ongoing, and this forum is not in a position to 
influence it much.  But we do need to know what direction that debate is 
taking, whether for better or worse, because it will influence the way in 
which we are able to speak, whether it be the way we prefer to think or no.    (02)

I wrote:    (03)

>> Whoa!  I fully agree that URLs locate lots of useful and functionally
>> different things, just as postal addresses do.  But if today it's a 
>> bank and
>> tomorrow it's a laundry or a residence or a casino, what "resource" is 
>> being "identified"?    (04)

Pat wrote:    (05)

> Well, according to Roy Fielding's REST model, which is endorsed by the 
> TAG, a resource is a function from times to 'representations' (which I 
> think here means not descriptions, but more like the sense in which the 
> webpage that my browser shows me is a 'representation' of the state of 
> your website at the moment I pinged it). So, the answer is: the (note, 
> singular) resource is a temporal function whose value is in quick 
> succession a representation of a bank, then of a laundry, then a casino, 
> etc...    (06)

Well, I have to admit that that is a model I had never before heard 
promulgated.  So I am at least grateful for the education.  You will pardon my 
reaction that this is, to borrow a Russian metaphor, an attempt to make candy 
from manure.    (07)

> This seems to make nonsense of the TAG assertion that URIs "ought" to be 
> stable, indeed eternal, in the sense  that they should always identify 
> the same resource; since there seems to be no way to distinguish a 
> single resource which looks like a chameleon from a succession of 
> resources each of which is rather more stable. I asked the TAG to 
> clarify this point, but they didn't take up the suggestion.    (08)

The "clarification" would doubtless have been a misnomer in any case.    (09)

I wrote:    (010)

>> What I said was that if the content to which a URI refers changes 
>> radically
>> from day to day, the URI doesn't identify "an information resource" in 
>> any useful sense.    (011)

Pat wrote:    (012)

> But it can still technically identify a single resource. There really 
> are sites like this, eg http://www.humanclock.com/clock.php  which 
> changes every minute.    (013)

This goes to my observation (below) that the "nature" of a resource is some 
combination of content, function and behavior.  The clock has constant 
function and behavior.  The exact content changes to fulfill that function, 
but the "functional content" is always the same -- it is the current 
population of the world.    (014)

But it is exactly this kind of variance that tells us we can't in general 
equate the "resource" at the location with the text of the web page.  The 
question here is whether the "information content of the web page" is the 
"population of the world at 17:00 UTC on 16 April 2007", or the "current 
population of the world", which are clearly distinguishable concepts.  I would 
not be uncomfortable arguing that the humanclock location corresponds to a 
"resource" that is a "service" rather than a "document".    (015)

I wrote:    (016)

>>  And thus the idea that the URI identifies something different
>> from a location is false.  If the purpose of a URI is to denote content,
>> function, behavior, as distinct from location, some one of those has 
>> to be consistent over time.
> Why?    (017)

If the content, function, and behavior of whatever is at the location have no 
commonalities over time, then all that is being designated is the location. 
It's a particular street corner, full stop.  It is not THE location OF 
anything in particular, except instantaneously.    (018)

>>  A bulletin board and a pulpit are just locations.    (019)

Ken said:
>>> Everything is a resource to someone, as it should be.  What we want to
>>> be able to do is differentiate resources so we use the one(s) most
>>> suitable for our needs.    (020)

I wrote:
>> Exactly.  But unless there are common conventions for that 
>> differentiation, 
>> all we have is a bunch of disorganized resources labeled according to 
>> hundreds
>> or thousands of incompatible schemes, most of which are not very good 
>> or very
>> useful.  Google has built a successful enterprise on the failure of 
>> the Web,
>> and its principal resources, to address that problem.  And there are 
>> many who
>> believe that that also is as it should be.    (021)

Pat said:
> Close. I believe that this is the way it WILL be, no matter how much any 
> number of people try to improve it. So we ought to get used to reality, 
> and learn how to deal with it :-)    (022)

I find myself having to agree.    (023)

I often cite the Serenity Prayer (attributed to Reinhold Niebuhr):
Grant me the serenity to accept the things I cannot change,
The courage to change the things I can,
And the wisdom to know the difference.    (024)

This does not, however, prevent me from undertaking efforts which I believe to 
have a very low probability of success, if only to fulfill Alexei Meystel's 
observation that "someday, someone will remember that this was said, and it 
will make a difference."    (025)

In engineering, you can't prevent the design, manufacture and sale of junk. 
But you can teach young engineers how to design and build quality, in the 
expectation that a few of them will actually have the opportunity.    (026)

>> IMO, the problem is that Internet is still the big city of the Middle 
>> Ages. ...    (027)

Pat said:    (028)

> Following your analogy, the other thing about the internet is that it is 
> getting bigger faster than we are learning how to use it.  Its like
> living on an expanding planet.    (029)

Absolutely.  But I think we are also only beginning to see the seismic 
instability that goes with planetary expansion, the consequent threat to 
fragile economic and social structures, and the draconian countermeasures the 
establishment will impose to protect itself from seismic events.  That too is 
how it WILL be, and that future may well be less rosy than the present.    (030)

> Maybe thats why it stays rather like the wild west.    (031)

My favorite analogy for the Internet has always been the Wild West.  (I can't 
say what possessed me to choose the late medieval city on this go.)  ;-)    (032)

-Ed    (033)

Edward J. Barkmeyer                        Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263                Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263                FAX: +1 301-975-4694    (034)

"The opinions expressed above do not reflect consensus of NIST,
  and have not been reviewed by any Government authority."    (035)

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