Re: JESS: certainty/confidence factor

Tue, 17 Oct 2006 09:17:48 -0700

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
"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:
 
 
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
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Institute for Information Technology  Institut de technologie de l'information
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-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of m u
Sent: Tuesday, October 17, 2006 12:36 AM
To: [email protected]
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

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