Composite Systems

Construction of likenesses using composite systems

A composite system involves constructing a face from separate features

e.g. identikit, photo-fit, e-fit

1^st generation systems were paper-based.

Nowadays they are computerised, eliminating the obvious lines between features and allowing for features and allowing for features and allowing for feature blending and changes in spacing.

Early systems were not always effective.

Second-generation systems use computers to draw a composite based on verbal description, adding “standard” features where there are gaps.

Study>Ellis et al

Ellis et al compared the accuracy of an early photo-fit system with hand-drawn sketches. Working from memory, the photo-fit system was more accurate than the sketch. However, with the target face present, the sketches were judged to be more accurate than photo-fits.

Evaluation

Early systems were limited

New-generation systems are more effective

Karpardis>found that e-fit system enabled confirmation of a suspect in 23% of cases.

Studies lack ecological validity. In real life witnesses do not have time to study the face, and the person using the likeness to identify a suspect will probably know the suspect. (E.g. colleague, neighbour)