Constructing identifiable composite faces: the importance of cognitive alignment of interview and construction procedure

Abstract

We investigated the impact of congruency between the witness interview and method used to construct a composite face. Experiment 1, using a typical feature-by-feature composite method, revealed that aligning cognitive processes during interview and face construction enhanced the effectiveness of composites compared with composites produced following unaligned (incongruent) procedures. Experiment 2 revealed that incorporating character judgements in the witness interview substantially enhanced identification of feature-based composites when constructing the central (internal) features first, suggesting that such judgements focus attention on this region of the face. Experiment 3 explored alignment of processes using an approach based on an evolutionary algorithm, a method requiring witnesses to create a composite by selecting from arrays based on the eye-region. A combination of character judgements, first for the whole face and then for the eye region, led to best-identified composites. Overall, results indicate that more effective composites are produced when both interview and construction procedures are aligned cognitively. Results are discussed with relevance to the theory of transfer-appropriate processing (Morris, Bransford, & Franks, 1977). Public Significance statement: This experimental study reveals that facial composites are much more effective as an identification aid if the witness interview used to elicit a description of the culprit draws on the same cognitive processes as the method used to construct the composite face. Findings are valuable to developers of facial composite systems, and are also relevant to police and forensic practitioners, all of whom should ensure that methods of face production are compatible with interviewing procedures used with witnesses and victims of crime.