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"Wisdom of Crowds" Works For Individuals Too
Posted by
kdawson
on Fri Jun 27, 2008 09:00 AM
from the I-am-large-I-contain-multitudes dept.
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.
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In related news... (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.
Re:In related news... (Score:5, 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)
Parent
Re: (Score:2)
I'd hazard a guess that us oldies would need longer between guesses than the young 'uns, since we're more likely to remember the previous guesses than a rap-music listening, zero attention span teen.
That is, the effect of increased accuracy should fall off with age.
Re:In related news... (Score:4, Informative)
Parent
Re:In related news... (Score:4, 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.
Parent
Re:In related news... (Score:4, 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.
Parent
Re: (Score:3, Interesting)
Good observation about the Gaussian distribution being necessary. Thought experiment: I am thinking of a number between one and a million. What's the likelihood that the average of a bunch of people's guesses are anywhere near the number I am thinking of?
So how long is the emperor of China's nose? (Score:5, Insightful)
Re: (Score:2)
Re:So how long is the emperor of China's nose? (Score:5, 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.
Parent
Re: (Score:2)
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.
Or maybe after 3 weeks you've forgotten your previous answer or have lost the psychological attachment to it and are not as nearly as likely to pick a new number in close proximity to the original.
What I'm saying is that maybe 6%* just represents the avg amount individuals are willing to stray from their original guess.
What the study really needed was intermediate data points between "immediately" and "3 weeks".
*shouldn't it be a 12% difference between the 1st & 2nd guess, which avgs to 6%?
Re: (Score:3, Interesting)
Nearly every one of them said yes.
The problem with this particular example from P&T (who are awesome despite doing this from time to time) is that this isn't an appeal to find a concrete value or fact, it is instead an appeal to a person's knowledge. Just like the questions asking about weapons of mass destruction were framed in a manner which directly appealed to the information people were being fed by the administration and in turn the media.
Had the questions been framed more like "If Iraq possesses
Re: (Score:2, Informative)
Most polls said people expected that we would find WMD and WMDs were found.
Re: (Score:2)
That's right. WMDs were even used... Though not by Iraqis: http://news.bbc.co.uk/2/hi/middle_east/4440664.stm [bbc.co.uk]
Re: (Score:3, Informative)
How is this informative? This is wrong. Read the wikipedia article [wikipedia.org]. Money quote:
A little biased (Score:5, Funny)
"600 jelly beans?"
"Higher"
"900?"
"Looower...."
The Delphi Method (Score:5, Interesting)
Another product of the RAND Corporation.
From the I-am-large-I-contain-multitudes dept.? (Score:5, Funny)
Do I contradict myself?
Very well then! I contradict myself!
Re: (Score:3, Funny)
My name is Legion, for we are many
Wisdom of the Crowds" (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.
Re:Wisdom of the Crowds" (Score:5, Funny)
Parent
Re: (Score:3, Interesting)
Explains (Score:5, 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?
Re:Explains (Score:5, 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.
Parent
Re: (Score:2, Funny)
This assumes, of course, that everything in life is like a jar of jellybeans.
Unfortunately, it's not. Life is like a box of chocolates. Ask Forrest's momma.
Re:Explains (Score:4, Insightful)
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.
Parent
Re: (Score:2)
Your comment violated the "postercomment" compression filter. Try less whitespace and/or less repetition.
Huh, that's a new one.
Re: (Score:2)
Actually I was kidding, really. It just wasn't that funny.
Gubmint (Score:2)
N.B. -- this does not apply to politics. In fact, the phrase "Political Science" may be turning into the biggest oxymoron of all time.
Measure Twice, Cut Once (Score:2)
Ah duh! (Score:5, Funny)
Re:Ah duh! (Score:4, Funny)
Parent
Re:Ah duh! (Score:5, Insightful)
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).
Parent
Re:Ah duh! (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.
Parent
Re:Ah duh! (Score:4, 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.
Parent
Re: (Score:3, Interesting)
I predict that if you ask the same person the same question over and over again even at wide intervals the answers will converge but not necessarily to the correct value (of course, that value may often be "You asked me that before. Bugger off!")
yea, no (Score:2, Funny)
Yes, a little right. No, not at all. Total bullshit. Yet also 100% right. Doorknob. Right about 30% of the time. Wait, what was the question?
Wisdom of crowds? (Score:2)
Usually what you get out of crowds is some form of mob rule, not wisdom.
Durr (Score:4, Insightful)
Um, three weeks is plenty of time to look up such an intriguing factoid on the Internet.
Should this be a surprise? (Score:5, 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.
Re: (Score:3, Funny)
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.
Apparently that feature of the brain is broken for the players of the [Insert Name of Hated Sports Team].
(Hey...I try to make my put downs fun for everybody!)
I call bs on the concept.. (Score:2, Insightful)
I read through the first few chapters of James Surowiecki's book in the bookstore. The only thing I found was a small (statistically speaking) number of anecdotes. Nothing really well researched (perhaps there were actual studies done later on).
I would say my main gripe is that the idea is often presented in an extremely poor manner. Like the author above does with the jelly beans.
It implies that the "popular mean" can express knowledge that isn't strongly represented in the group already. I.e. Clearly
Sorry, can't resist... (Score:3, Funny)
Crowds not wise in sports betting, that for sure (Score:2)
I was deeply involved in sports betting for a while. One of the first things any serious sports bettor learns is that if everyone else likes the same team as you, then start to worry.
There are several websites dedicated to come up with a public consensus on wagers. They were always a must-see for me but only as another piece of information (oddly, it's just as dumb to bet along with the crowd as it is to bet against it.)
Yes, this is gambling, but it's not like betting red or black in roulette. There here ha
Short vid about Wisdom of the Crowds (Score:3, Interesting)
Intervals (Score:2)
It sounds like this is just an example of someone making a confidence interval; "I know the answer is in a certain range, so I'll make two guesses and it should probably be in there."
If each guess is made using a different model, then you're adding more "information" to the guess. Then there's more total information in the average, than in each guess on it's own.
But what do I know, I'm not a psychologist. I could just be making stuff up.
The wisdom of averages (Score:4, Interesting)
Sounds Strangely Like (Score:2)
Forest for the trees. (Score:2)
Things get awkward when people talk about harnessing the power of crowds to improve complex predictions. A question like, "What will the price of oil be in five years?" is damn near impossible to answer without a time machine because it completely fails to factor in unpredictable economic & political disruptions (9/11, some guy inventing a portable fusion generator in his basement, alien invasion, global war, or pandemic). In fact, the financial markets are a great example of "the wisdom of crowds" loo
Minsky's Emotion Machine (Score:3, Interesting)