There are inherent problems in building management of uncertainties into
rule-based systems. See
D. E. Heckerman, E. Horvitz. On the Expressiveness of Rule-Based Systems
for Reasoning with Uncertainty. AAAI - 87, Sixth National Conference on
Artificial Intelligence, Seattle, WA, 1987.
http://smi-web.stanford.edu/auslese/smi-web/reports/SMI-87-0194.pdf
James C. Owen wrote:
Actually, certainty and/or confidence factors are discussed in detail in
the Giarratano and Riley's book, complete with an introduction to
probability theory as well as many other concepts not normally used in
business software. This approach was used with great success in
diagnosis when designing MYCIN, an early rulebased system dealing with
medical diagnosis, as well as many of some other types of
prognostication software.
It isn't "easily" implemented in straight Jess nor in any other forward
chaining package, BUT it can be done with a bit of thought up front
concerning tracking tables, maximum probabilities, etc. After all, you
wouldn't want to have a 250% chance of something happening. But it does
deal with the problem of a 70% chance that something will happen and a
10% chance that something will not happen. The other 20% is the problem
child. Is it doubt or confidence? This kind of logic is also used
extensively in the financial fraud detection and CRM software. _Great_
stuff but requires 70% thought and 30% coding. Something to which we,
as programmers, are not usually accustomed. :-)
And you are right - a fuzzy logic extension relieves a lot of the manual
programming. But, on the other hand, it also adds some restrictions to
what you can and can not do. I've often wondered why vendors such as
ILOG, FIC, Pega, MindBox, Haley, etc., etc. don't include something like
that. But, then, they've never really done anything constructive with
full opportunistic backward chaining, have they? Well, time to get off
the soap box and get back to work. However, I, for one, and probably
several others on the list, would be most interested in what you find
out using Jess.
SDG
jco
James C. Owen
Senior Consultant
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
http://www.kbsc.com
"Never give in--never, never, never, never, in nothing great or small,
large or petty, never give in except to convictions of honour and good
sense. Never yield to force; never yield to the apparently overwhelming
might of the enemy.''
The speech was made 29 October 1941 to the boys at Churchill's old
public [private] school, Harrow--not Oxford nor Cambridge.
On Oct 17, 2006, at 5:49 AM, Orchard, Bob wrote:
There are no certainty or confidence factors implemented in Jess.
There is an extension
that allows fuzzy reasoning to handle uncertainty, called FuzzyJess.
If this might
suit your needs see:
http://www.iit.nrc.ca/IR_public/fuzzy/fuzzyJToolkit2.html
It is mentioned in Jess in Action. At some point I was going to add
certainty/confidence
factors but I never did ... many ways to implement and I'm still not
convinced of
its usefulness.
Bob.
Bob Orchard
National Research Council Canada Conseil national de recherches
Canada
Institute for Information Technology Institut de technologie de
l'information
1200 Montreal Road, Building M-50 M50, 1200 chemin Montréal
Ottawa, ON, Canada K1A 0R6 Ottawa (Ontario) Canada K1A 0R6
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(613) 952-0215 Fax / télécopieur
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Government of Canada | Gouvernement du Canada
-----Original Message-----
*From:* [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] *On Behalf Of *m u
*Sent:* Tuesday, October 17, 2006 12:36 AM
*To:* jess-users@sandia.gov <mailto:jess-users@sandia.gov>
*Subject:* JESS: certainty/confidence factor
Hi all,
I've tried to search in JESS in Action book but couldn't find
anything about certainty or confidence factor. Is this feature not
yet implemented in JESS?
thanks,
irejai
--
Samson Tu email: [EMAIL PROTECTED]
Senior Research Scientist web: www.stanford.edu/~swt/
Stanford Medical Informatics phone: 1-650-725-3391
Stanford University fax: 1-650-725-7944
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