THE WISDOM OF THE CROWD is the process of taking into account the collective opinion of a group of individuals rather than a single expert to answer a question. A large group’s aggregated answers to questions involving quantity estimation, general world knowledge, and spatial reasoning has generally been found to be as good as, and often better than, the answer given by any of the individuals within the group. An intuitive and often-cited explanation for this phenomenon is that there is idiosyncratic noise associated with each individual judgment, and taking the average over a large number of responses will go some way toward canceling the effect of this noise.This process, while not new to the information age, has been pushed into the mainstream spotlight by social information sites such as Wikipedia, Yahoo! Answers, Quora, and other web resources that rely on human opinion.
The process, in the business world at least, was written about in detail by James Surowiecki in his book The Wisdom of Crowds.
In the realm of justice, trial by jury can be understood as wisdom of the crowd, especially when compared to the alternative, trial by a judge, the single expert.
In the political domain, sometimes sortition is held as an example of what wisdom of the crowd would look like. Decision making would happen by a diverse group instead of by a fairly homogenous political group or party.
Research within cognitive science has sought to model the relationship between wisdom of the crowd effects and individual cognition.