“…An airport security officer's (screener's) decision on whether a bag is harmless ( target absent ) or might contain a prohibited item ( target present ) determines whether a secondary search must be conducted at airport security checkpoints (typically using explosive trace detection and a manual search of passenger bags; Sterchi & Schwaninger, 2015). Table 1 presents the four possible decision outcomes and associated terminology from visual search studies (e.g., Biggs & Mitroff, 2015; Eckstein, 2011; Wolfe, 2007, p. 99), signal detection theory (SDT; e.g., Gescheider, 1997, p. 106; Green & Swets, 1966, p. 34), and X-ray baggage screening (e.g., Cooke & Winner, 2007; Schwaninger, Hardmeier, & Hofer, 2005).…”