Assessment of X-ray image interpretation competency of aviation security screeners

The competency of an aviation security screener to detect prohibited items in X-ray images quickly and reliably is important for any airport security system. This paper details the requirements and principles for reliable, valid, and standardized competency assessment as well as different methods that can be applied for this purpose. First, the concepts of reliability, validity and standardization are explained. Then, threat image projection (TIP) as a means to assess X-ray image interpretation competency is discussed. This is followed by a discussion of computer-based tests, which provide another often more reliable and standardized option for measuring x-ray image interpretation competency. Finally, the application of computerbased tests in an EU funded project (VIA Project, www.viaproject.eu) are presented.