Saturday, February 23, 2008

On "fuzzy" logic

Leanne having pointed out that not many people other than engineers know what I mean when I refer to "fuzzy logic," I thought a quick explanation would be in order:

Can you define "old"? For example, is a 41-year-old man "old"? ("Yes!" emphatically answer Anya, Natasha and Kinya, all of whom habitually address me as "starik," i.e., "old guy.") How about a sixty-year-old? How about someone 110? What if that 110-year-old is a sea turtle? (Okay, I admit that last one is cheating a bit.)

If you look at, say, the Social Security Administration, their attitude is that nobody is old when he is 62 years and 364 days old; but the next day, instantly, poof! old guy. Now this is absurd, and recognizing that it's absurd is really all that "fuzzy" logic is about: it's about recognizing that you start off not at all old, and then you get sort of older, and then you're kinda old, and after a while you're pretty old, and after a while later you're definitely old, and after a while it's like, whoa, don't tell me you're still around.

"Binary" definitions say, "Either you're old, or you're not." They deal only with yes-or-no questions. "Fuzzy" definitions lend themselves to questions like, "On a scale from one to ten..." Binary: "Are you happy, or are you not?" Fuzzy: "How happy are you?"

Thus "pregnancy" is a purely binary issue; if someone asked a lady, "How pregnant are you?" it would be an absurd question. "Old," on the other hand is fuzzy.

Now, logic is just the rules for thinking carefully and clearly. And thus "fuzzy logic" is not "careless and confused logic" -- fuzzy logic is just the rules for thinking carefully and clearly about fuzzy things.

Whaddaya think, Leanne -- think that'll help 'em?

Oh, and on a related topic... I think I've mentioned this before, but there are only 10 kinds of people in the world: those who think in binary, and those who don't.

3 Comments:

At 11:46 PM, Anonymous Anonymous said...

Pretty good "quick" explanation for an engineer. :-) -- Remember, I'm married to one so I can say that! :-) Mine likes explaining so much he's now teaching. That's at least part of why I know a LITTLE about fuzzy logic.

Leanne

 
At 3:49 PM, Blogger Kris with a K said...

love the binary joke! bwa ha ha!

 
At 10:45 AM, Anonymous esteban said...

Wierd...Leanne's comment sounds an awful lot like something my wife would say...

...and you can get the binary joke on a T-shirt - my colleague wears one. Try thinkgeek.com if interested.

 

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