On March 7, 1907, the English statistician Francis Galton published a paper which illustrated what has come to be known as the “wisdom of crowds” effect. The experiment of estimation he conducted showed that in some cases, the average of a large number of independent estimates could be quite accurate.
This effect capitalizes on the fact that when people make errors, those errors aren’t always the same. Some people will tend to overestimate, and some to underestimate. When enough of these errors are averaged together, they cancel each other out, resulting in a more accurate estimate. If people are similar and tend to make the same errors, then their errors won’t cancel each other out. In more technical terms, the wisdom of crowds requires that people’s estimates be independent. If for whatever reasons, people’s errors become correlated or dependent, the accuracy of the estimate will go down.
But a new study led by Joaquin Navajas offered an interesting twist (转折) on this classic phenomenon. The key finding of the study was that when crowds were further divided into smaller groups that were allowed to have a discussion, the averages from these groups were more accurate than those from an equal number of independent individuals. For instance, the average obtained from the estimates of four discussion groups of five was significantly more accurate than the average obtained from 20 independent individuals.
In a follow-up study with 100 university students, the researchers tried to get a better sense of what the group members actually did in their discussion. Did they tend to go with those most confident about their estimates? Did they follow those least willing to change their minds? This happened some of the time, but it wasn’t the dominant response. Most frequently, the groups reported that they “shared arguments and reasoned together”. Somehow, these arguments and reasoning resulted in a global reduction in error. Although the studies led by Navajas have limitations and many questions remain, the potential implications for group discussion and decision-making are enormous.
查看答案与解析
答案
B
解析
【导语】本文是说明文。没有人是一座孤岛，文章陈述了“群体智慧”效应。实验表明，在某些情况下大量独立估计的平均值可能是相当准确的。 【详解】 主旨大意题。根据第二段内容“This effect capitalizes on the fact that when people make errors, those errors aren’t always the same. Some people will tend to overestimate, and come to underestimate. When enough of these errors are averaged together, they cancel each other out, resulting in a more accurate estimate. If people are similar and tend to make the same errors, then their errors won’t cancel each other out. In more technical terms, the wisdom of crowds requires that people’s estimates be independent. If for whatever reasons, people s errors become correlated or dependent, the accuracy of the estimate will go down. (这种效应利用了这样一个事实，即当人们犯错误时，这些错误并不总是相同的。有些人常常会高估，或者低估。当这些误差中有足够多的误差被平均在一起时，它们会相互抵消，从而产生更准确的估计。如果相似的人倾向于犯同样的错误，那么他们的错误不会相互抵消。从更专业的角度来说，群众的智慧要求人们的估计是独立的。如果由于任何原因，人们的错误变得相关或依赖，估计的准确性就会下降)”可知，本段阐述了人们所犯的错误不总是相同的，各不相同的误差平均在一起，相互抵消就会产生更准确的估计，讨论了独立估计的平均如何由于误差的消除而产生更准确的预测。因此本段主要解释了“群体智慧”效应这一现象的基本逻辑。故选B。 【点睛】