Rob Freeman wrote:
> On Mon, Feb 1, 2010 at 7:54 PM, John F. Sowa <sowa@xxxxxxxxxxx> wrote:
>> ...
>> There is no such thing as a one-size-fits-all ontology that
>> can cover chess, hiking, programming, eating, cooking, chemistry,
>> surgery, driving a car, and football. For most of those subjects,
>> a very large part of the background knowledge will *not* be
>> expressed in either verbal patterns or some version of logic. (01)
> No contest on the impossibility of a "one-size-fits-all ontology". (02)
> Also no contest on the need for "background knowledge". (03)
This separation is something that Cyc worked on for years through its
"microtheory" (context) system, but then (for reasons of philosophical
purity) to a great extent discarded. (04)
The basic microtheory system had at the top level, merely concepts
referring to logic, with "vocabulary" microtheories defining concepts
in various fields and with "theory" microtheories that can provide rules
for the vocabulary microtheories. A naive physics context has general
rules as to how physical objects interact, while a formal physics context
would be used for solving questions in an Advanced Placement physics test.
When reasoning with a set of contexts, concepts and rules defined in
unrelated contexts would not be considered by the reasoner. (05)
When reasoning about chess, game playing and spatial contexts are needed
as well as a basic temporal context, but no contexts about physics or
physical objects, chemistry, biology, or human relations are needed. A
special microtheory with the rules of chess would be needed as well. (06)
Football requires game theory, but also naive physics, naive human anatomy,
and sports contexts. Cooking would use naive physics and food ontologies,
but not game theory or anatomy. Etc. (07)
> But why can't "background knowledge" too be represented in patterns
> among text, patterns of word use etc? (08)
A problem here is the multiplicity in meanings of words and phrases. (09)
> I agree the "background knowledge" must be found outside any simple
> sentence being interpreted. That goes without saying. You would have
> to find patterns in the whole language.
>
> Think of it as a machine learning problem. I'm talking about learning
> a whole ontology, theory, even logic, directly from raw patterns in
> text, then using it to interpret a sentence in context. (010)
This seems like a far more complex problem than ontologizing all of
"common sense knowledge" (Cyc's goal) by hand. (011)
> The machine learning problem has been attempted before. The new thing
> is that we agree anything you learn must be partial. Extremely partial
> I believe. Specific to each sentence, or more. That is what makes this
> machine learning effort different from all earlier efforts. But, given
> that we've agreed whatever you learn must be partial, what will be the
> limits on what can be learned? (012)
Learning from pattern analysis requires large data sets. Not learning
from individual sentences (which I doubt is what you mean by extremely
partial). To learn partial meanings for words and phrases in different
contexts, the corpus would have to be divided up into different contexts.
If this is not done manually, the problem of metaphorical usage of words
would constantly arise. (013)
-- doug (014)
> -Rob
=============================================================
doug foxvog doug@xxxxxxxxxx (015)
"I speak as an American to the leaders of my own nation. The great
initiative in this war is ours. The initiative to stop it must be ours."
- Dr. Martin Luther King Jr.
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