Social media are a way of using the wisdom of the crowd. This wisdom can be a powerful thing. The famous story of how the operating system Linux became successful is a good example of something that an individual (Linus Thorvalds in this case) could never have pulled off by himself. But of course there are also many examples in history of a crowd being utterly stupid. What is this strange thing called “wisdom of the crowd” and how can we use it in the projects that we undertake?

In March of 2011, he Dutch TV showed a documentary about this. It started with the first time in history that the wisdom of the crowd had been researched and documented in a more or less scientific way. In 1906, Francis Galton was at a cattle market, where a competition was held to guess the weight of an ox. For a small amount of money, the visitors could take part in the competition by submitting their guess on a piece of paper. There were some 800 participants and the winner was the person whose guess was the most accurate. Galton did not expect this crowd to be very wise; it was a cattle market after all. He wanted to prove this hypothesis by making an analysis of the guesses. So he asked if he could borrow the 800 slips of paper.

To his surprise, the analysis Galton made showed that the average of the 800 guesses was a lot better than the best individual guess. The average of all the guesses was 1197 lbs and the actual weight of the ox was 1198 lbs. Of course this crowd knew a bit about cattle – and they could all see the ox from up close. That is probably why the remake of this competition over the internet a little over 100 years later did not work out as well.

The TV documentary showed a cow and asked the audience what they thought its weight was. The average of the answers was 552 kg. The best individual answer was right on the mark: 740 kg. Much better than the average! So the wisdom of the crowd does not always work. What probably made it worse is that people who did not know anything about cows used the internet to find out how much a cow weighs. If one googles the weight of a cow, one finds a few Dutch sites about cows that rank high in Google and that estimate the weight of a full grown cow between 500 and 600 kg.

The wisdom of the crowd works best when the people in the crowd know something about the subject and when they have access to relevant information. In a project, you will hopefully have people who know something about the subject matter your project is dealing with. And if you want to use their wisdom, it helps a lot if you make sure they have access to all relevant information.

Update: recent research shows that two more aspects are important when large crowds perform simple estimation tasks: diversity and independence. Especially this finding about independence makes the research interesting. When the members of the crowd gain information about the estimates of others, their confidence grows, but the accuracy of the crowd as a whole drops dramatically. Social media are an easy way to gather information about the estimates of others, increasing our confidence but at the same time blurring our vision! What to do? Good stuff for another post. Stay tuned…