

The Crowd Performs at the 95th Percentile - vrish88
http://trada.com/blog/2010/10/15/example-how-crowdsourcing-works/

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RonileSille
Interesting. Does this mean group think isn't as bad as we thought?

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_delirium
It depends on the thing being estimated. This approach works great when the
main problem is variance among estimates, not overall bias. In that case,
aggregating a bunch of predictions reduces the variance, as the biased-low and
biased-high individuals cancel each other out. Variance between individual
guesses often follows something like a bell curve, so the average is just the
center of the bell curve. If the curve was centered over the right location,
then the average is better than the vast majority of individual predictions,
which are off to one tail or another.

There are plenty of things where the average prediction is systematically off,
though, like people's estimates of how likely they are to die of various
causes. In that case, averaging predictions won't produce the right result.

