The Influence of Statistics on Social Influence

June 15, 2011 By Aminda

A recent post looked at a study out of Switzerland that found an exception to the belief that the wisdom of the crowd is, on average, more accurate than the wisdom of an individual. The study identified the “social influence effect”, in which individuals had access to the answers of others. The effect of questioning one’s own results as compared to others led to a decline in accuracy.

A commentary on this study posted in a Wall Street Journal article received some heated debate and discussion arguing that WSJ writer Jonah Leher, misread the results of the study.This blog post by Nicholas Carr sums up the accusations, primarily that the wisdom of crowd effect was only shown in one instance and that even in that instance, the only reason it was close to correct was because the median answer, not the mean, was used. In most cases, the average answer provided by the crowd was wrong, contradicting the wisdom of crowd effect.

While the researchers themselves do not misreport this finding, they certainly downplay it. Their introduction cites previous studies supporting the wisdom of crowd effect and focuses on their findings that the effect can be affected when a variable such as social interaction is introduced. Carr explains how the researches do so through normal, acceptable statistical manipulation and provides a concise, humorous conclusion to the debate.

Even in its most basic expression, the wisdom-of-crowds effect seems to be exaggerated. In many cases, including the ones covered by the Swiss researchers, it’s only by using a statistical trick that you can nudge a crowd’s responses toward accuracy. By looking at the geometric mean rather than the simple arithmetic mean, the researchers performed the statistical equivalent of cosmetic surgery on the crowd: they snipped away those responses that didn’t fit the theoretical wisdom-of-crowds effect that they wanted to display. As soon as you start massaging the answers of a crowd in a way that gives more weight to some answers and less weight to other answers, you’re no longer dealing with a true crowd, a real writhing mass of humanity. You’re dealing with a statistical fiction.

Share on      
Next Post »

Reader Comments


Today, with more 235,000,000 vehicles on the road; Driver Safety is of utmost importance on all our minds. Tragically a Life is lost every 13 minutes. My latest Invention is related to "People Saving People - Driving Safely," via an accident prevention device. Unfortunately Toyota has had some recent problems regarding Safety issues. This device will help eliminate some of those problems, and other negative connotations. (Let Toyota be the First!)

It would be exciting for Toyota to introduce this gadget to the public. It will become a new car manufacturers Dream. Insurance companies will love it. A Genesis in Driver Safety, guaranteed to help SAVE LIVES.


Posted by shirley servance on June 21, 2011

Observing great progress in the development of Software as a Service (SaaS), Cloud Computing, and computing utility services, Nicholas G. Carr (aka Nick), the author of The Big Switch: Rewiring the World, From Edison to Google talks about the vision of CIOs and the like for Cloud Computing in the video. See Anubhav Saxena, VP -- Marketing, HCL Technologies exploring the scope of building a common workable system to meet ever increasing demands in End User Computing with him.
Posted by Edward Jhon on June 16, 2011

Add your Comment

[LOGIN FIRST] if you're already a member.

fields are required.

Note: Your name will appear at the bottom of your comment.