Featured Research

from universities, journals, and other organizations

Repetition of rare events could reduce screening mistakes by security

Date:
November 4, 2013
Source:
Carnegie Mellon University
Summary:
The failure to detect infrequent, but obvious security threats at airport screenings and other checkpoints may have less to do with incompetence or poor training than a human tendency to overlook rare events. But a researcher suggests guards could improve their detection rates the same way adults learn vocabulary words -- through repetition.

Inattentional blindness monitor.
Credit: Image courtesy of Carnegie Mellon University

The failure to detect infrequent, but obvious security threats at airport screenings and other checkpoints may have less to do with incompetence or poor training than a human tendency to overlook rare events. But a Carnegie Mellon University researcher suggests guards could improve their detection rates the same way adults learn vocabulary words -- through repetition.

Related Articles


In experiments that simulated multiple-camera video surveillance, study participants failed to correctly detect threats about 45 percent of the time when exposed to two threat events over the course of two hours. But the error rate dropped to 25 percent when encountering 25 events in the same time span. Most missed events were blatant, such as someone brandishing a knife.

"If people know what they're looking for and haven't seen it for some time, or their attention is focused elsewhere, they won't necessarily see what they're looking for, even when it is in full view," said Judith Gelernter, associate scientist in the School of Computer Science.

Gelernter will report her findings Nov. 13 at the IEEE International Conference on Technologies for Homeland Security in Waltham, Mass. The experimental results suggest that one way to make threat detection more effective is to have screeners routinely encounter and respond to simulated threats.

Failure to see what is before the eyes, particularly when concentrating on something else, is a phenomenon known as "inattentional blindness." This is a problem not just for airport screeners, border guards or building security personnel, but for any occupation in which someone is looking for anomalies that occur infrequently, such as radiologists reading CT scans, or pathologists looking for cancer in biopsy slides.

Inattentional blindness is a form of selective attention. Gelernter explained that it occurs because the brain must strike a balance between accuracy, which can take time, and efficiency. When a person has seen a lot of a certain pattern, such as law-abiding behavior, the brain might continue to register that pattern, despite what is seen to the contrary, in an attempt to be efficient, she said.

Using simulated threat events to give screeners additional opportunities to see rare events would make them seem less rare and make it more likely that actual threats would be noticed, she said. This strategy could be applied not only to security screeners in airports, but to other occupations in which inattentional blindness is a concern.

In the Carnegie Mellon experiments, 108 people underwent half-hour training to learn how to detect low-level and high-level threats. During the two-hour experiment that followed, 10 interior building views alternated to cover four quadrants of a computer monitor, with each view lasting for a minute, which is similar to actual surveillance video. Participants spent most of their time counting and categorizing hats worn by people in the videos, a task that demanded concentration and memory. But they also were told to summon police with a mouse click when they detected threats.

The subjects were randomly divided into three groups of 36; the only difference between the videos seen by the groups was the number of threat events that each group saw during the experiment -- two, nine or 25. Gelernter said the experiment was unusual for an inattentional blindness study because it lasted for hours, told participants just what to look for and gave them multiple chances to see the rare events.

This study was supported by a grant from the Army Research Laboratory's Army Research Office and a Berkman Faculty Development Grant from Carnegie Mellon.


Story Source:

The above story is based on materials provided by Carnegie Mellon University. Note: Materials may be edited for content and length.


Cite This Page:

Carnegie Mellon University. "Repetition of rare events could reduce screening mistakes by security." ScienceDaily. ScienceDaily, 4 November 2013. <www.sciencedaily.com/releases/2013/11/131104152756.htm>.
Carnegie Mellon University. (2013, November 4). Repetition of rare events could reduce screening mistakes by security. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2013/11/131104152756.htm
Carnegie Mellon University. "Repetition of rare events could reduce screening mistakes by security." ScienceDaily. www.sciencedaily.com/releases/2013/11/131104152756.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Science & Society News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

After Sony Hack, What's Next?

After Sony Hack, What's Next?

Reuters - US Online Video (Dec. 19, 2014) The hacking attack on Sony Pictures has U.S. government officials weighing their response to the cyber-attack. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Spokesman: 'NORAD Ready to Track Santa'

Spokesman: 'NORAD Ready to Track Santa'

AP (Dec. 19, 2014) Pentagon spokesman Rear Adm. John Kirby said that NORAD is ready to track Santa Claus as he delivers gifts next week. Speaking tongue-in-cheek, he said if Santa drops anything off his sleigh, "we've got destroyers out there to pick them up." (Dec. 19) Video provided by AP
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Science & Society

Business & Industry

Education & Learning

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins