Factors limiting face matching at passport control and in police investigations

Face matching entails a comparison between two faces that are unfamiliar to an observer, who must then decide whether these depict the same person or different people. Despite the ubiquity of face matching in practical settings, such as passport control and police investigations, laboratory research has established that this task is highly error-prone, and that many of these errors derive from visual characteristics of to-be-compared face stimuli. Such characteristics include factors such as image quality, lighting, and natural changes in personal appearance, which influence the visual correspondence between face stimuli. In this chapter, factors that are likely to limit face-matching accuracy in real-world settings are reviewed, with the aim of providing insight into how these influence the accuracy of this process and how subsequent errors may be mitigated.