ontolog-forum
[Top] [All Lists]

Re: [ontolog-forum] Architectural considerations in Ontology Development

To: ontolog-forum@xxxxxxxxxxxxxxxx
From: John F Sowa <sowa@xxxxxxxxxxx>
Date: Fri, 15 Feb 2013 23:15:54 -0500
Message-id: <511F07FA.4090606@xxxxxxxxxxx>
Ed, Doug, Paul, and Steven,    (01)

JFS
>> Every attempt to replace a critical, working system with a new
>> one that could not interoperate during the transition has failed.
>> The greater the discontinuity, the greater the ensuing disaster.    (02)

EJB
> This is simply not true of replacement of a major system.  The good
> management practice is to operate both systems side by side, feeding
> the transactions to both (by some means) and, as experience and confidence
> with the new system becomes established, appointing a changeover date for
> retirement of the legacy system.    (03)

That confirms my point.  As you said, "good management practice" is
to run both systems side by side to ensure that they produce identical
results.  For ontology, that implies that any new ontology must be
able to interoperate with the implicit ontology of the legacy code.    (04)

JFS
>> The duration of that transition is usually *decades*, not years.    (05)

EJB
> Not in my experience.  If the new system was properly designed,
> the legacy system itself can be retired within the year.    (06)

That depends on (a) the size and complexity of the system and
(b) how you define the term 'new system'.  The Ship of Theseus is
still relevant -- all the parts are being replaced, but each version
contains much of the design and many of the parts of the previous one.    (07)

For example, the Sabre system for airline reservations was jointly
developed by IBM and American Airlines to run on the IBM 7094 in
the early 1960s.  But a great deal of the design and the ontology
was based on the SAGE system built by IBM for the Strategic Air
Command in the late 1950s. (It was the largest vacuum-tube machine
ever, and it continued to run until the 1980s when the only place
where they could get replacement tubes was the Soviet Union.)    (08)

Sabre was rewritten several times to run on System/360, 370, etc.,
and everybody on this list probably still uses versions of it (directly
or indirectly) to make reservations today.  None of the original code
survives, but much of the original design and ontology is still in use.    (09)

DF
> If the definitions of language elements (type, relation, function, subtype,
> instance of, if-then[-else], there Exists, forAll, not) is part of the
> "upper level ontology",then this would not be true since all of the axioms
> and definitions at the mid and low levels are based on such elements.  Cyc
> actually defines such terms in its upper level ontology, but it is clear
> that that is not what Doug Lenat meant.    (010)

Any Kn. Rep. language (CycL, for example) is based on some version of
logic.  The items in parentheses in your first two lines are included
in FOL or any extension, such as CycL.  I would reserve the term
'ontology' for the definitions and axioms of particular relations,
types, and functions that use the core logic, but are not part of it.    (011)

The Cyc upper level specifies a large number of types, functions,
and relations.  It also includes many axioms for them, but it leaves
most of them underspecified.  Every microtheory that has an axiom that
uses a term t adds more detail that specializes t.    (012)

PT
> The mother of all system disasters happened nearly 50 years ago when
> the IBM suits and their ilk...    (013)

I spent 30 years working for IBM, and I have a lot of "war stories"
from the past.  Some of them are good, but many are painful.    (014)

PT
> Their idea of interoperability was "make it the best electric typewriter 
>ever".    (015)

I sat in on some painful presentations by executives from IBM
Lexington.  But I have to admit that IBM consistently produced
the best keyboards, which still survive in Lenovo Think Pads.    (016)

PT
> The software vendor-consultant complex plays a large role in inducing
> suboptimal system design and deployment... And regardless of system
> benefits or performance, software vendors are eager to extend vendor
> lock-in through proprietary formats and closed systems.    (017)

Yes.  Some of the most painful aspects of Windows are the result
of Bill Gates doing his worst to make it incompatible with OS/2.
And some of the worst aspects of SQL are the result of certain
vendors who did their worst to enforce lock-in.    (018)

SEZ
> So at some point it will pay to go back and do it over - if for
> competitive reasons alone - but, again, the cost to "do it right"
> will be deferred in favor of the cost to do it quickly and cheaply,
> deferring and increasing critical costs to the poorly considered future.    (019)

All those points require a lot of qualification.  By "do it right"
do you mean using today's "best practices" or waiting until a new
set of best practices come along tomorrow?    (020)

I like the three goals of diversity, heterogeneity, and interoperability
that Tim Berners-Lee emphasized in 2000.  That strategy would allow
legacy systems to continue running while the developers upgrade them
by incremental changes.  It would also allow today's "best practices"
to be replaced by incremental changes in the future.    (021)

John    (022)

_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J    (023)

<Prev in Thread] Current Thread [Next in Thread>