Error analysis and threat magnitude for carry-on bag inspection

A major part of aviation security research is prediction and improvement of systems performance to address different threat vectors. The current paper arises from the application of several ideas from the area of non-destructive inspection (NDI) to X-ray screening of carry-on baggage. The premise is that if findings from the security domain are similar to those in the NDI domain, then much prior research on inspection becomes directly applicable to security applications. Simulated threats were presented to 22 experts and 24 novices using 3 threat categories, 4 viewpoints and threats at 3 different image scales. Along with speed-accuracy trade-off, the applicability of "PoD Curve" analysis from NDI reliability was also explored along with individual differences. Results indicate support for speed-accuracy trade-off (SATO) and PoD models applied to security inspection, with large effects of expertise and smaller effects of age. Improvised explosive devices (IEDs) also produced a different pattern from guns or knives indicating that studies should include IEDs to be broadly applicable.