X-ray screening is an inherent part of the security process at airports, let alone in other sensitive areas, such as courts or prisons. In the European aviation sector, security officers operating X-ray machines are mandated to undergo training for six hours every six months. Sandrina Ritzmann and Claudia Lüchinger discuss why training of X-ray image interpretation is extremely important, what role computer-based training (CBT) plays and what characteristics and aspects are important for high-quality CBT.
Depending on the number of passengers or cargo handled, security officers (screeners) deal with X-ray images for several hours a week. So do they still need training? The answer is yes. Research has shown that visual knowledge of threat items and their appearance in X-ray images (so-called knowledge-based factors) is one essential prerequisite for good X-ray detection performance. This knowledge has to be acquired and maintained through regular training as the X-ray image often differs substantially from the regular appearance of an object Thus, training is needed to ensure that security officers know which items are prohibited and what they look like under X-ray examination in order to successfully detect them. A number of scientific studies have shown that computer-based training (CBT) can significantly improve the X-ray image interpretation competency of screeners.
Advantages of Computer-based Training
Given the fact that training is needed, the next question is: what kind of training is optimal to enhance the X-ray image interpretation competency of screeners? The type of training required depends on the skill that needs to be acquired. To specifically target the visual knowledge of prohibited items, CBT has several advantages over face-to-face classroom training, practical training, or training on-the-job (although these forms are certainly useful for other skills). One advantage of CBT lies in its function as a standardised training tool; once a training system has been implemented, it can be used effectively by a large number of people. Furthermore, individual progress is flexible and not dependent upon an instructor or other trainees (as it would be in a class setting) allowing for higher training efficiency. The flexibility of CBT is also important because it facilitates the implementation of distributed practice (whereby, for example, every X-ray screener might receive 20 minutes training every week); general research on human learning and training has shown that regular, distributed practice sessions leads to better results than ‘massed’ practice (several hours of training once every few months). Another important aspect of CBT is its capacity for progress measurement and skill assessment. For instructors in a face-to-face setting, it is very challenging to measure progress or assess skills in an objective and reliable manner, especially when dealing with a large group of people. CBT also provides direct user interaction and feedback, which can easily make it more motivating than instructor-centred training.
Administration features of CBT systems provide various instruments to the administrator to target and monitor users’ performance; the management tools enable setting training goals and the continuous reporting provides an overview of each user’s training behaviour, training hours and results.
However, not every CBT programme is worth implementing just for the sake of it. There are important aspects to consider when the quality of CBT is assessed. Two facets will be highlighted in more detail below.