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Re: [ontolog-forum] Globally unique definitions (was tasteful tags)

To: "John F. Sowa" <sowa@xxxxxxxxxxx>
Cc: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Pat Hayes <phayes@xxxxxxx>
Date: Sat, 10 Mar 2007 00:00:27 -0600
Message-id: <p06230901c217f2c1c1cd@[]>
>The global postal address (name, street, city, country)
>was adequate as a globally unique id for data transmission
>(snail mail) for centuries.    (01)

Only for about two centuries, and only in some countries. It didn't 
work in China until well after WW2, for example, and there are still 
many areas of the world where it does not work.  But in any case, 
this kind of quibbling is silly: we are clearly talking about 
computerized networks.    (02)

>   And we've had globally unique
>ids for computer-like usage since the 1930s (Social Security
>Numbers on punched-card machines).    (03)

A SS number isn't going to do you much good outside the USA. Large 
though it is, the US is less than 5% of the world's total population 
(300 million in 6.7 billion)    (04)

>  They also supported data
>storage and transmission (by putting cards on a truck and
>shipping them to globally unique addresses).    (05)

Again, not a lot of use across continental distances.    (06)

>These techniques may sound primitive by today's standards,
>but there is nothing in principle that is different about
>URLs except speed and convenience.    (07)

I profoundly disagree. The chief difference in principle is that the 
transmission can be done without human aid, and at near-instantaneous 
speeds, and is now genuinely world-wide.    (08)

>  On a related note, see
>the proposed standard for TCP/IP links via carrier pigeon:
>    http://www.ietf.org/rfc/rfc1149.txt
>That may be jocular, but it could work.
>JFS>> With the advent of computer systems, programming tools
>>>  forced those "footnotes" to be made explicit, and they
>>>  have done so remarkably well since the 1950s.
>PH> I guess I don't follow what you mean here.
>The globally unique ids such as addresses and SSN's were
>put on the computer.  By piling up enough of them, you
>could get a unique key for anything in the world you wanted
>to designate.    (09)

No, you couldn't. But even if you were right, what has this got to do 
with footnotes?    (010)

>That technique has been used in database
>systems for over 40 years.
>Admittedly, the methods were not uniform across all
>implementations, they've been working for years.
>PH> There were no global references before the Web.
>No.  See above.
>PH> Well, you can do things like this with redirects and so on.
>>  People often don't bother in simple cases, but there is a
>>  lot of PHP out there. For example, my URI
>But that involves building an ad hoc redirecting kludge on top
>of a global system instead of building an ad hoc global kludge
>on top of a local system.    (011)

It is not an ad hoc kludge. Redirection is part of the basic 
machinery of the internet, and has been since day one. Well, maybe 
day two. Read Roy Fielding's thesis.    (012)

>JFS> I still remember the early days of PCs, in which names
>>  of files and disk drives were hard coded in the programs
>>  and people complained about those hard coded connections.
>>  They pleaded for greater flexibility by parameterizing
>>  the connections.  But now the SemWeb has returned to the
>>  good (?) or bad (?) old days with hard coded connections.
>PH> Not at all. In fact nothing could be further from the truth,
>>  cf http://www.w3.org/Provider/Style/URI
>That reference just recommends some naming guidelines.  What I
>was talking about is a context-dependent reference system, which
>could be dynamically linked into various contexts.    (013)

So was the reference cited.    (014)

>  That is the
>typical programming-library notion that programmers have been
>using since the early '60s.
>For example, there are two fundamentally different ways of
>linking a term, say "vehicle", into an environment:
>  1. Globally unique: a fixed definition that is independent
>     of any other definition for "vehicle" in any environment.
>  2. Context dependent: the term "vehicle" is linked to whatever
>     definition for "vehicle" is used in the current environment.
>Method #1 is the default for the WWW, and method #2 must be
>supported by some ad hoc kludge.    (015)

Really, John, you should find out more about the actual Web 
architecture before saying such crazy things. URIs are globally 
unique. But that says nothing about global uniqueness of 
*definitions*, and a URI is not an address, it is an identifier. The 
process of getting from the URI to the 'place' where the identified 
resource is located - the http protocol specification - can be very 
complicated and intricate, and can easily accommodate your method #2. 
And this is not an ad hoc kludge, it is part of the most basic 
protocol definition of the entire Web, the process by which 
information is transferred across the entire internet; and in fact it 
is widely used in large professional websites.    (016)

>  Method #2 is the default for
>programming libraries, and method #1 is supported by a variety
>of different methods (including the option of using a URI).
>And I'd also like to mention a third approach:
>  3. Unique, but mobile:  a globally unique id, which allows
>     agents to move around the WWW while retaining their own
>     identity, independent of the computer (or device or cell
>     phone) on which it happens to be located    (017)

Yes, URIs can do that, but not ...    (018)

>-- and without
>     any assistance (or even recognition) from the sender or
>     the domain name servers of the Internet.    (019)

...this. Nor should they. Why would you want any Internet-based 
communication process to be done without assistance from the Internet 
servers? Seems crazy to me.    (020)

>Method #3 can be simulated by implementing a virtual network
>on top of the Internet, and I'm sure that such things will
>proliferate over time.    (021)

Well, there have been many such schemes. People at IHMC have one, 
which supports the CmapTools server/client system with a worldwide 
distribution. And like all such schemes, it is extremely hard to 
maintain, less efficient than simply using the Web, and doomed to 
ultimate failure. The fact is that all such schemes are inevitably 
overtaken by the exponents in Moore's Law within a few years. Its 
far, far cheaper to just use the actual Web, as well as being more 
robust.    (022)

>All of these are important naming schemes, and they should all
>be supported by some systematic scheme instead of being built
>by an ad hoc kludge (such as a special-purpose PHP program).    (023)

By your conventions, any programming counts as an ad-hoc kludge. PHP 
is widely used, and so are several other redirecting systems. They 
all work within the overarching architectural and semantic specs 
which define the Web. They *work*, to repeat. Why are they kludges??    (024)

Pat    (025)

>John    (026)

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