Feeding the five thousand -- or was it three? Researchers claim most crowd estimations are unreliable

Aug 25, 2011

The public should view crowd estimation with scepticism, say the authors of a study published today in Significance, the magazine of the Royal Statistical Society and the American Statistical Association, as they suggest more reliable alternatives to current estimating methods.

Estimates of sizes vary greatly, and the success of an event is often measured by the size of the crowd. Organisers of the 2007 "Stop the War" demonstration in London reported crowds of 60,000, whereas the police reported just 10,000. The US Government's estimate of the crowds at Obama's inauguration ceremony was 1.8 million, while other were much less, closer to one million. "In the absence of any accurate estimation methods, the public are left with a view of the truth coloured by the beliefs of the people making the estimates," claims Professor Paul Yip, of the University of Hong Kong, one of the authors of the study.

Such a huge in estimates is currently not unusual and suggests the use of crowd sizes as a political tool. Larger crowd sizes are a means of recruiting others to the cause, and it is more difficult for the authorities to ignore demands. "The authorities are sometimes put in a difficult position," says Yip. "It is important to highlight the shortcomings of existing estimating methods."

In today's study, the authors reveal several more accurate, more reliable methods of estimating crowd sizes. Currently, even when searching for the truth, there is a wide margin of error. The authors recommend organisers and authorities use an area x density estimating method for static crowds, which reduces the margin of error to less than 10%. Furthermore, they have devised an entirely new method of reliably estimating mobile crowds. Two inspection points are placed along the route where the number of participants is estimated, not too close together and with one near the end. In applying this two-inspection-point method to the Hong Kong 1st July march (a demonstration of widely-varying claimed size and of great political sensitivity) since 2003, more reliable estimates can then be obtained.

"It is important to rectify the myth of counting people. The public would be better served by estimates less open to political bias. Our study shows that crowd estimates with a margin of error of less than 10% can be achieved with the proposed method," Yip concludes.

Explore further: World population likely to peak by 2070

add to favorites email to friend print save as pdf

Related Stories

Does the wisdom of crowds prevail when betting on football?

Nov 15, 2010

the number of points by which a strong team can be expected to defeat a weaker team—are supposed to reflect the "wisdom of crowds." But a new study in the Journal of Consumer Research found that crowds don't have a clue ...

Global war deaths have been substantially underestimated

Jun 20, 2008

[B]Research paper: 50 years of violent war deaths from Vietnam to Bosnia[/B] Globally, war has killed three times more people than previously estimated, and there is no evidence to support claims of a recent decline in ...

Recommended for you

World population likely to peak by 2070

Oct 23, 2014

World population will likely peak at around 9.4 billion around 2070 and then decline to around 9 billion by 2100, according to new population projections from IIASA researchers, published in a new book, World Population and ...

Bullying in schools is still prevalent, national report says

Oct 23, 2014

Despite a dramatic increase in public awareness and anti-bullying legislation nationwide, the prevalence of bullying is still one of the most pressing issues facing our nation's youth, according to a report by researchers ...

Study examines effects of credentialing, personalization

Oct 23, 2014

Chris Gamrat, a doctoral student in learning, design and technology, recently had his study—completed alongside Heather Zimmerman, associate professor of education; Jaclyn Dudek, a doctoral student studying learning, design ...

Data indicate there is no immigration crisis

Oct 22, 2014

Is there an "immigration crisis" on the U.S.-Mexico border? Not according to an examination of historical immigration data, according to a new paper from Rice University's Baker Institute for Public Policy.

User comments : 0