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"Wisdom of Crowds" Works For Individuals Too

Posted by kdawson on from the I-am-large-I-contain-multitudes dept.

ideonexus writes "Take a crowd of people and have them guess how many jelly beans are in a jar, and the average of their answers will be remarkably accurate. Now researchers have found the same goes for asking one person to guess about the same thing several times. Accuracy improved when the individual was given longer periods of time between guesses." The anonymous author of the Economist piece, not quoting the researchers, says the finding bolsters the "generate and test" model of creative thinking.

23 of 158 comments (clear)

  1. In related news... by morgan_greywolf · · Score: 4, Funny

    In related news, students were found to do far better on multiple choice tests when given an unlimited number of guesses at each question. Even students that didn't study eventually got As.

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    1. Re:In related news... by smallfries · · Score: 4, Insightful

      Not quite... but you are close. It sounds like you're pointing out that anyone will get lucky if given enough chances. These guys are claiming that the average will converge to the ground truth over time. This would need to have guesses with some Gaussian distribution about the correct answer.

      If the guesses were uniformly distributed then the average wouldn't tend to the correct answer over time. Of course what is described in the summary has nothing to do with the wisdom of crowds as it is commonly thought of (i.e in markets) where shared information is vital. Instead it is simply an artifact of sampling (which is why the longer gaps are necessary for better accuracy)

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    2. Re:In related news... by bunratty · · Score: 3, Informative

      I think you need another class in statistics. It doesn't matter whether the guesses are normally or uniformly distributed. If the guesses are distributed around the correct value, the average over many guesses will converge to the correct value. All this shows is that when someone makes an estimate, they are usually close, and they overestimate about as much as they underestimate. The average of those guesses will then be more accurate than any one guess selected at random. The guesses probably are normally distributed, but that the fact that the average of the guesses converges to the correct result in itself does not prove that they are.

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    3. Re:In related news... by Free+the+Cowards · · Score: 3, Insightful

      You state the really cool thing about this but somehow completely miss it!

      You say, "If the guesses are distributed around the correct value...." Well, why would they be? They're guesses! There's no reason to expect one person's guesses to be centered on the correct value if they don't know the correct value. But this study shows that they are centered near the correct value, even though the person doesn't know what that value is.

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    4. Re:In related news... by Free+the+Cowards · · Score: 3, Insightful

      That would be a flaw if I ever discussed "a bunch of people", but I never did.

      The interesting thing here is not that the individual can guess a number close to the true value. What's interesting is that if he guesses more than once, the average is closer to the true value than his initial guess. This is unexpected and a little weird.

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  2. So how long is the emperor of China's nose? by Watson+Ladd · · Score: 5, Insightful

    Wisdom of crowds only works when the crowd has some information about the situation. Look at polls about Iraqi weapons of mass destruction for more details.

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    1. Re:So how long is the emperor of China's nose? by zappepcs · · Score: 4, Insightful

      Exactly. Penn and Teller asked a group of people if the chemical Dihydrous Monoxide should be banned. Nearly every one of them said yes. The wisdom of crowds is not in and of itself some sort of magic. It is merely an interesting observation.

      That your own guesses seem to exhibit the same 'average' correctness as a crowd is bad science IMO. Once you guess at a problem, you're subconsciously directed to think of that problem, thus getting more than a knee jerk reactionary guess. The longer you have to think about it, the longer you have to assimilate information pertaining to the answer.

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  3. A little biased by InvisblePinkUnicorn · · Score: 5, Funny

    Granted, the tests were done on the Price is Right.

    "600 jelly beans?"

    "Higher"

    "900?"

    "Looower...."

  4. The Delphi Method by Illbay · · Score: 4, Interesting
    http://en.wikipedia.org/wiki/Delphi_method

    Another product of the RAND Corporation.

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  5. From the I-am-large-I-contain-multitudes dept.? by lilomar · · Score: 4, Funny

    Do I contradict myself?
    Very well then! I contradict myself!

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  6. Wisdom of the Crowds" by phoenixwade · · Score: 5, Insightful

    The idea that a group guessing is more accurate than an individual guess, and if you make more than one guess the mean or average of the guesses is more accurate than a single guess?

    So, in real world terms, 1000 rednecks are going to be more accurate than one Harvard graduate? (assuming the graduate in question isn't our current President) (if we were guessing the number of pickled eggs in a pickle jar, I'd have to agree... Otherwise, I'm somewhat skeptical of how well this translates beyond the estimation of things.

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    1. Re:Wisdom of the Crowds" by thethibs · · Score: 4, Funny

      More like it takes a thousand Harvard graduates in conference to show the common sense of one redneck. But who's counting?

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  7. Explains by Paranatural · · Score: 4, Funny

    This explains why there's so much informative discussion here at slashdot. N o one knows much of anything, but if you throw enough wild assed guesses at something, one of them is bound to be right, right?

    1. Re:Explains by HairyCanary · · Score: 4, Insightful

      No, I don't think so. It wouldn't be "one of them is bound to be right" -- it would be something more along the lines of "with enough posts, the consensus is likely to be close to reality."

      This assumes, of course, that everything in life is like a jar of jellybeans.

    2. Re:Explains by virgil_disgr4ce · · Score: 3, Insightful

      Har har, but that's not the idea. If only one of them is right it's not the average. I interpret it more like this: intuition is a product of subconscious information processing. The brain is a pattern-recognition machine, and is generally very good at that. I would hazard a guess that if you average out everybody's intuitions ("first guesses"), some of the people are "overthinking" things, but many are just going with their gut, and the pattern recognition and extrapolation that's going on constantly anyway in your brain is often onto something.

      The "generate and test" idea is something I've made great effort to more consciously embrace in my creative endeavors. People decry "quantity over quality," but what I've found is that you simply can't just brood over an idea and "work on" the idea until it's "perfect" and then execute it--you have to create prototypes and test them, and the more you do this, the better you get at creating good prototypes in the first place. Still, it's remarkable how difficult it can be to convince yourself of this.

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  8. Ah duh! by mspohr · · Score: 5, Funny

    The amazing discovery they made is that when people had time to think about a question, they gave better answers. This is profound.

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    1. Re:Ah duh! by Yvanhoe · · Score: 3, Funny

      And it took a study to prove that. Now let's have a control group that will be base on faith...

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    2. Re:Ah duh! by JustinOpinion · · Score: 4, Insightful

      In fact there is some research that suggests for certain kinds of decisions, more thought is actually counter-productive. That is, initial "gut" decisions are sometimes more optimal than carefully-considered ones (where "optimal" is measured by longer-term happiness/regret of decision). (For instance, check this writeup of this paper, or the associated Slashdot submission.)

      The point is that while thinking long and hard about some problems can be helpful (e.g. designing something complex and technical), for other kinds of problems, added thought can hinder (e.g. when there are many confounding unknowns).

    3. Re:Ah duh! by John+Hasler · · Score: 3, Insightful

      They didn't say that the second answer was better. They said that the average was better. It would be interesting to know if the second answer was, on average, better than the first.

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    4. Re:Ah duh! by Talderas · · Score: 5, Funny

      The point is that while thinking long and hard about some problems can be helpful (e.g. designing something complex and technical), for other kinds of problems, added thought can hinder (e.g. when there are many confounding unknowns).

      So that explains why most /.ers are single.

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  9. Durr by Anonymous Coward · · Score: 4, Insightful

    Um, three weeks is plenty of time to look up such an intriguing factoid on the Internet.

  10. Should this be a surprise? by Kohath · · Score: 4, Insightful

    I thought this was understood.

    This is how you are able to catch a ball. Your brain doesn't do a physics calculation and determine where the ball will land. It guesses, watches, refines the guess, repeats, and eventually the guess is close enough so your hand is in the right spot to catch it.

  11. The wisdom of averages by thethibs · · Score: 3, Interesting

    So what we've always thought was the wisdom of crowds turns out to be the wisdom of averages. That does make more sense.

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