Posted by Jay Livingston
James Surowiecki begins The Wisdom of Crowds* with the true fable of Francis Galton and the ox. Galton was at a country fair where an ox was on display, and the locals could submit guesses as to what the weight of the ox would be when it was slaughtered and dressed. Galton, a statistician and a bit of a eugenics fan, figured that the guesses of the less savvy would dilute the accuracy of the smart money guesses. So he kept track of the roughly 800 entries.
No individual guess had the exact weight – 1198 pounds. But when Galton caculated the mean of all guesses, it turned out to be 1197 pounds, much closer than the best individual guess. That was in 1906, and while Surowiecki presents other examples of successful crowd-sourcing, I’m not sure if there has been an exact repeat of the Galton-ox scenario.
We’re many months away from county fair season in New Jersey, so we have no oxen to be weight-guessed. But The New Republic has come close to replication: crowd sourcing the weight of the governor.**

(The ox is on the left. For a larger view, click on the image.)
Unfortunately, TNR closed the contest with only 19 entries, a far cry from Galton’s 800. But for what it’s worth, the mean was 334 pounds.
-----------------------------
* The SocioBlog has had several posts on this topic. See this one for an example and for links to others.
** I didn’t know whether I should put the photo of the Governor behind an NSFW gate. I even hesitated to use it, but then, Galton’s fairgoers too had to guess the weight of the ox before it was dressed. (I found the photo here. That site credits Wonkette.)