All good and well, but I think Surowiecki weakens his case by mixing examples that don't quite rightly belong together, cherry-picking some behavior. It's an attractive populist message, which should start up the warning bells to be careful at least.
First, his first big example is the crowd "picking" the weight of a hog by having the mean almost exact (say 1187 pounds to 1188 pounds actual). Uh, okay, that proves what? I would guess that if you went from county fair to county fair, the mean of the means would deviate quite a bit, but the averages of the 10 best hog breeders would be much more accurate and deviate less. Just a hunch that the item in question was a fortuitous instance. Try it with marbles in a very large jar rather than the weight of a hog. By what I take is the author's thesis is that we could get 6 billion humans to vote on the weight sight unseen and they'd get it right because they're a wise crowd, or perhaps I'm not reading him right - he doesn't lead me towards understanding the wisdom. The lack of rigor is added to when you hear that a group of traders in Iowa pick the Presidents better than the Gallup poll. Of course they do, or you wouldn't be hearing about them, you'd be hearing about a group of stock car drivers in Alabama who pick better than the Gallup poll. Of how many crowds trying to be correct, how many show Surowiecki's "wisdom"? 1/1000? Now, it might be that Iowa is situated enough between Montana myopia on the right and New York myopia on the left that it balances to be less deceived than those in other places. But meanwhile, a group somewhere else like Texas, just as authoritatively a "crowd", would be mixing signals and betting wrong - getting it right in the Bush years, getting it wrong in the Clinton years perhaps. (And considering that an election might be decided by a few electoral votes or a single Supreme Court justice, what really does that prove, except that you might be as predictable as a coin toss?) Now, I thought the American public was very wise at the end of the Clinton years when it was not swayed by the Lewinski scandal. But if I were Republican, I might think the public very stupid and gullible. We're into value decisions, and is the public more or less consistent on values versus deciding how much something weighs and whether the sky is a particular hue? The Google example is something different. You're able to model what people expect by modelling lots of people. Especially if people are more satisfied with 20 different answers, you can cross-correlate the answers from a million people and make sure the top 20 don't resemble each other, and that will be much much more satisfactory than if every one points to the same URL. But this only tells us that it's useful to model people's expectations if we want to derive an answer that people expect (and want). An important result, and I like Google, but very different from crowds being inherently "wise". Crowds are inherently human, and Google caters to that humanity. But its results on WMD's may not satisfy a right-winger or a left-winger or neither, though folks in the middle might be happy. I just clicked "I Feel Lucky" for "Monica", and there was some singer I'd never heard of - I thought the name Monica had been retired with Lewinsky, but I'm wrong. So Google is more like having the house working for you rather than against you in Vegas (unless you're doing clicks for ads, but let's not go there). But that still doesn't address "wisdom", it addresses "humanness". We're doing a bell curve on human expectations, not on right vs. wrong. Now what happens if Google aggregates Pakistan with Germany, or instead separates Asia from Latin America from North America? Is Google deriving wisdom to appeal to all sectors equally, or splitting by domain ending/country (certainly I get different answers depending on what languages I check, but does it change based on my IP address as well?). If I'm an African Googling from New York, will I get the same satisfactory results as if I'm Googling from Dakar, or will Google miss my demographics? Some of the mathematical work on deriving a neutral stock portfolio is very interesting and very similar in some respects to finding the mean "wisdom" of the human crowd (or subsets thereof). You end up with different classes of investors with different risk and gain requirements, so different appropriate investment tools. And you can track performance of various popular stocks, mutual funds, people who bet the Dow vs. those who are conservative or risky. If Surowiecki really wants to test his hypothesis, he should get together the minimum number of people that make a "wise" crowd, get them to choose stocks, and then figure out the mean choice, and they all take the plunge. I apologize if I sound negative, but I think he would have been better off trying to model the different agents involve and develop a complex theory that might have some simplistic analogies. People with experience will on average do better than people with no experience in most fields. People with accurate information will do better than those without accurate information, most of the time. But there are some types of decisions that are simply counter-intuitive, and this might depend on culture and time - whether the earth is flat, whether rock 'n roll is harmful, whether rent control is healthy, whether gay marriage is "okay". Some of these judgments have measures, some not. There are some areas where expert knowledge is of no help, but that's a far cry from saying lay knowledge in aggregate is always more "wise" than expert knowledge to whatever measure. Giles Bowkett wrote: > I haven't read it but Surowiecki presented at South By Southwest this > year (because of the Web 2.0 connection) and I've listened to the > podcast of this presentation a couple times while working out. I > definitely recommend it and the book's on my list to read. > > Judging from that presentation, it sounds as if the book would have > probably had a more accurate but less catchy title if he had called it > "The Wisdom Of Decision-Making Markets," because what he says in the > speech is that it's really about how aggregate decisions, summed from > the decisions made by all individuals in a large group of people > competing against each other, consistently outperform the decisions of > the best-informed experts in those groups. > > ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
