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Airport baggage screeners may need continuing education, study indicates
Jim Barlow, Life Sciences Editor
217-333-5802; jebarlow@illinois.edu
4/27/04
CHAMPAIGN, Ill. —
Baggage screeners have just seconds amid loud airport noises and the
pressure of rushed airline travelers to scan X-rays of carry-on items
for weapons. How good they are at finding one may depend on the specificity
of their training, say researchers at the University of Illinois at
Urbana-Champaign.
The findings, published in the May issue of the journal Psychological
Science, suggest that initial training of federal airport screeners
needs to last long enough for them to be exposed to a variety of weapons,
and continuing education may be necessary to expose screeners to potentially
new and unexpected ones.
The research was conducted at the Beckman
Institute for Advanced Science and Technology at Illinois, using
two-color X-ray images of carry-on baggage containing knives provided
by the Federal Aviation Administration, which funded the study. Eye-tracking
techniques captured where and how quickly the participants scanned through
clothing, hair dryers, pill bottles and other items in each X-rayed
piece of luggage to find a weapon.
The laboratory training of 16 volunteer young adults helped them to
become more efficient in spotting knives in the baggage, but their improvements
did not carry through when the sizes of the knives were changed in newly
examined images, said principal investigator Arthur F. Kramer, a professor
of psychology.
“We found that the effects of training were beneficial,”
Kramer said. “Clearly people improved on their abilities to spot
specific weapons in a search. However, we found that training, for the
most part, was relatively specific to the items on which screeners were
trained. There wasn’t a lot of transfer. If the expectation is
that we can train screeners on one set of weapons and expect them to
transfer that ability to another kind of weapon, that is not the case.”
The X-rayed baggage – 89 pieces in all – was presented on
a 19-inch monitor. Two sets of four differently sized knives were used
and inserted at random locations and orientations. Each participant
took part in five sessions of 300 trials each.
“We found that training did not have much of an impact at all
on how quickly they got their eyes to the area of a weapon,” Kramer
said. “What improved was how quickly they detected a weapon once
they looked into the right region. They became better able to differentiate
the weapon from other materials, but not better able to get their eyes
into the right location more quickly.”
When different, unfamiliar targets were introduced, the number of eye
movements of the participants increased before the targets were found,
and the probability of finding them decreased.
The goal is to reduce both the numbers of false identifications and
the actual misses. That will require an approach that develops the capacity
to perceptually organize and recognize a variety targets in security
imagery, Kramer said. “You have to train relatively broadly if
you want to get better across the board. I think that’s increasingly
important given the creativity of terrorists.”
In addition to Kramer, four other Illinois researchers were involved
in the study: Beckman Fellow Jason S. McCarley (now a professor at Mississippi
State University and who will join the Illinois faculty this summer);
doctoral student Walter R. Boot; Christopher D. Wickens, professor of
psychology and head of the Institute
of Aviation’s Human Factors Division at Willard Airport; and
Eric D. Vidoni, an undergraduate student.
