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ONE YEAR LATER : HOW SCREENER PERFORMANCE IMPROVES IN X-RAY LUGGAGE SEARCH WITH COMPUTER-BASED TRAINING

A total of 273 luggage search operators from eight airports performed an x-ray competency assessment test on two occasions, with a median of 427 days apart (s.d. = 172.06 days). These screeners are part of an employment setup where recurrent computer-based training and on-the-job assessment are in action, resulting in a large performance ability improvement between the two tests. Using Drury’s inspection model (1975) accompanied by signal detection measures (Green and Swets, 1966), it was found that screeners became faster for both search and decision time, as well as becoming more accurate in their detection of threat items. It is concluded that longitudinal benefits are found when screeners are part of an organised training environment that is scientifically based and individually adaptive.