## Featured Research

from universities, journals, and other organizations

# Airport Security: Researcher Proposes Statistical Method To Enhance Secondary Security Screenings

Date:
February 3, 2009
Source:
University of Texas at Austin
Summary:
A researcher has found that secondary security screening at airports is mathematically flawed, and has identified a way to select people for screenings more efficiently and fairly.

A researcher at The University of Texas at Austin has found that secondary security screening at airports is mathematically flawed, and has identified a way to select people for screenings more efficiently and fairly.

William H. Press, a professor of computer sciences and integrative biology, proposes a method called square root bias sampling to statistically choose who should be taken aside for a more thorough screening. The method applies to situations where selection is based on individual profiles such as ethnic or racial profiling.

His finding is published in the Proceedings of the National Academy of Sciences.

For the paper, Press supposes that whoever is doing the sampling has accurate statistical information that some people are more likely to be terrorists than others.

The statistical effectiveness of profiling selected groups has been relatively unexamined and Press said he does not think that it is effective.

Press's idea applies when there is a primary screening that is uniform, and then the possibility of a secondary screening based on an individual's "profile" (their "prior probability").

At an airport, the primary screening is everyone who shows up and goes through the checkpoint, while the secondary screening is when someone is selected for a more thorough search.

The way it works starts this way: Say that someone from the profiled group, Group P, is 16 times more likely to be a terrorist than someone from the average group, Group A.

Using the square root bias, people from Group P should be screened only four times more often then people in Group A (four is the square root of 16). That reduces the number of people from Group P who are subjected to repeated screenings, but it still screens people from Group P more than the average person.

Press said the method makes the best use of scarce resources to screen people while not screening the same people again and again, as happens now.

An astrophysicist-turned-computational biologist, Press was looking for a way to sample long sequences of DNA when he hit upon square root bias sampling as a solution.

After arriving at the method himself, he surveyed the literature and found that Ruben Abagyan, a professor at the Scripps Research Institute in La Jolla, Calif., had used a similar method in a different context.

Story Source:

The above story is based on materials provided by University of Texas at Austin. Note: Materials may be edited for content and length.

University of Texas at Austin. "Airport Security: Researcher Proposes Statistical Method To Enhance Secondary Security Screenings." ScienceDaily. ScienceDaily, 3 February 2009. <www.sciencedaily.com/releases/2009/02/090202174811.htm>.
University of Texas at Austin. (2009, February 3). Airport Security: Researcher Proposes Statistical Method To Enhance Secondary Security Screenings. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2009/02/090202174811.htm
University of Texas at Austin. "Airport Security: Researcher Proposes Statistical Method To Enhance Secondary Security Screenings." ScienceDaily. www.sciencedaily.com/releases/2009/02/090202174811.htm (accessed July 24, 2014).

## More Science & Society News

Thursday, July 24, 2014

### Featured Research

from universities, journals, and other organizations

### Featured Videos

from AP, Reuters, AFP, and other news services

Boeing Ups Outlook on 52% Profit Jump

### Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) — Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

### Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) — America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Six Indicted in StubHub Hacking Scheme

### Six Indicted in StubHub Hacking Scheme

AP (July 23, 2014) — Six people were indicted Wednesday in an international ring that took over more than 1,000 StubHub users' accounts and fraudulently bought tickets that were then resold. (July 23) Video provided by AP
9/11 Commission Members Warn of Terror "fatigue" Among American Public

### 9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) — Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters

## 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:
from the past week

## In Other News

... from NewsDaily.com

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