John, (01)
You certainly make a strong case for the development of
"module-specific" ontologies
that are limited in scope to the information flow along communication paths. (02)
However, it should be also very clear that the information flow ontology
for the communication between A and B is fundamentally dependent
on knowledge of what A and B do with that information. (03)
This point seems rather obvious to me but I'm not sure how obvious it
may be to this group.
Perhaps your last example might help: (04)
> As another example, the format of a date is critical, but it's
> irrelevant whether any system that uses the date applies the axioms
> of situation calculus or pi calculus or whether it uses a 3-D or
> a 4-D ontology for space and time. Different systems could use
> different axioms internally. (05)
If the information communicated from A to B includes a "date" for some
event that happened in system A,
then a 3D vs. 4D ontology for space/time could make a big difference
w.r.t. what that "date" means for system B. (06)
If A is a sail-propelled spacecraft travelling at 1/2 light speed from
Earth to Alpha Centuri, (the closest star to Earth, about 4 light years
away)
and B is an operator on Earth receiving a message from A stating
something like: "A passed the mid-point between Earth & Alpha Centuri
July 4, 2020",
then this message would be vague w.r.t. the "Earth time" when A did pass
that mid-point. Did A measure it w.r.t. a clock onboard of the spacecraft?
If so, did it compensate for the effects of relativity on the rate at
which its clock advances? Does A makes instead all of its calculations
in terms
of Earth time? (07)
I hope it is obvious that beyond the ontology behind the information
itself, there are other ontologies that are important
to make sure that all parties involved in the communication are
semantically aligned w.r.t. the meaning of that information. (08)
However, the same argument John makes for modularizing the ontology of
information flow applies equally well to modularize
the ontology describing the use of that information by the systems
involved in the communication. We don't need to know everything
that Amazon does to communicate effectively w/ Amazon; however, we need
to have some knowledge about Amazon (e.g I can purchase
a bread-making machine; but, to the best of my knowledge about Amazon, I
wouldn't go to Amazon to purchase baked bread for dinner). (09)
-- Nicolas. (010)
John F. Sowa wrote: (011)
> Jim,
>
> Your concern is justified, if all we could produce
> was a collection of unrelated modules:
>
> > Regarding John Sowa's suggestion of a collection
> > of modules, I question if it is possible to achieve
> > semantic interoperability with this approach, since
> > we will certainly have n-squared modules?
>
> But what we have today is a problem of N-squared
> communication paths among N *large* systems.
>
> A few days ago, Rick Murphy made a point, which I strongly
> endorsed: focus on the information flow along those paths.
> That change of focus has several implications:
>
> 1. When two systems A and B communicate, they always
> communicate about some subset of services on which
> they need to interoperate. For example, system A may
> be Amazon.com's purchasing system, while B might be
> some book publisher's sales system.
>
> 2. Both A and B have many other communication links among
> themselves and with their other customers, suppliers,
> employees, and agencies of various governments.
>
> 3. The ontology of the communication flow between A and B
> is a tiny subset of the entire ontologies of everything
> involved in both businesses. It's not practical or
> necessary to align the entire ontology of either company
> with the other.
>
> 4. Since Amazon has such a large share of the market for books,
> they have the power to dictate an ontology for the kinds of
> products they buy and the formats of how the transactions
> are performed. Company B, therefore, tells some database
> administrator to align some aspect of B's database to the
> categories and formats of A's purchasing system.
>
> 5. That task-oriented alignment, however, has a minimal effect
> on the overall ontology of Company B. Since Amazon is so
> large, it forces other suppliers to make similar alignments.
> Eventually, Amazon's ontology and formats become one of
> many de facto standards for electronic commerce.
>
> That's part of the modularity issue: It's task oriented,
> bottom up, and focused on information flow. Many such modules
> have evolved over the years. They're not going away, and they
> will be used indefinitely.
>
> Another part of the modularity issue is top down and focused on
> the details of internal processing, not on external information.
> This is where a detailed specification is used, either in procedural
> code or declarative axioms. But the internal details that are
> significant parts of a company's ontology are mostly irrelevant
> to the information flow along communication lines.
>
> What passes along communication lines are primarily names of
> entities classified in categories. For example, _War and Peace_
> is the title of a book, ten copies of which must be shipped from
> Company B to Amazon for a given price on a given date. Axioms
> about time and the differences between situation calculus and
> pi calculus for reasoning about time are not relevant to this
> transaction. They may be very relevant to programs running
> in System A or System B, but it's irrelevant whether A and B
> use the same or different axioms at each end of the channel.
>
> In an earlier note, Paul Prueitt made the point that vocabularies
> are more important than logic. For external information flow, I
> would agree that vocabularies are extremely important, but I would
> also insist that the formal specification, either in programs or
> in logic, is extremely important for the *internals* of A and B.
>
> Basic point: Interoperability among systems depends primarily on the
> channels for information flow, which are always highly specialized
> for particular kinds of tasks:
>
> 1. The information systems of any large company may interoperate
> on a daily basis with thousands of other systems around the world.
> It is unrealistic to require a global alignment of the full
> ontologies of all the categories and axioms of all those systems.
>
> 2. Any particular system may have many channels that are dedicated
> to many different tasks, each of which involves only a small
> subset of the total ontology of the system.
>
> 3. Most of the axioms that specify the internal computation and/or
> reasoning that takes place inside a system are *not* relevant
> to the information flow along any particular channel.
>
> 4. Task-oriented alignments of the vocabularies of symbols that
> pass along any channel are essential, but only a *minimal* subset
> of the complete definitions of those symbols need to be aligned.
>
> Two banks, for example, may have very different kinds of programs
> specified by very different ontologies for processing checks. But
> when a transfer for X dollars occurs, they only need to agree on
> the axiom that $X is deducted from one account and added to another
> account.
>
> As another example, the format of a date is critical, but it's
> irrelevant whether any system that uses the date applies the axioms
> of situation calculus or pi calculus or whether it uses a 3-D or
> a 4-D ontology for space and time. Different systems could use
> different axioms internally.
>
> John Sowa
>
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