Rare Prohibited Items Harder to Detect by Airport Screening

Rare Prohibited Items Harder to Detect by Airport Screening

Illustration image (123rf)

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Illustration image (123rf)
Illustration image (123rf)

Airport security X-ray screeners are trained to spot dangerous objects in luggage – but a new study finds that humans doing image-based item recognition tend to overlook unusual items, letting them slip by.

Two brain scientists from Duke University downloaded data from a smartphone game called Airport Scanner that simulates a Transportation Security Administration airport security checkpoint, challenging players to find hidden prohibited items in X-ray scan-like images of bags.

According to Fierce Homeland Security the game data has the advantage of letting researchers compare the percentage of spotted items to the number of actual prohibited items – something that in the real world would be hard to collect, to say the least. The researchers, Stephen Mitroff and Adam Biggs, focused their analysis on “elite” players of the game, meaning they had already been exposed to examples of the game’s total of 78 potential illegal items,

iHLS – Israel Homeland Security

What they found, based on more than 20 million examples, is that ultra-rare prohibited items – 30 of the total items, which showed up less than .15 percent of the time in the game–were detected only 27 percent of the time.

As a result, airport screeners may be conditioned to find more ordinary and run-of-the-mill prohibited items such as pocket knives or incorrectly packed prescription medications as opposed to a gun in a carry-on bag, since they see guns very rarely.

Previous research cited in the paper suggests that the ultra-rare-item effect could be mitigated by providing image searchers with a burst of typically low-prevalence items. That’s thought “to ‘reset’ the searchers’ criterion to a more effective state.”