A rate-them-all lineup procedure increases information but reduces discriminability

Prior research has investigated ways to optimize identification performance, but an open question concerns exactly what variable should be optimized. One reasonable way to optimize performance is to maximize discriminability, which is achieved by increasing correct identifications of guilty suspects while simultaneously decreasing false identifications of innocent suspects. Another reasonable way to optimize performance is to maximize the information about the guilt or innocence of the suspect, which is best achieved by ensuring that a confidence rating is always made to the suspect. In a typical lineup, however, limited information about the suspect is obtained if the witness picks a filler or rejects the lineup. One proposed solution to that problem is to have the witness provide a confidence rating to every member of the lineup (a rate-them-all lineup). But what effect, if any, does a rate-them-all procedure have on discriminability? To answer that question, we compared a rate-them-all lineup procedure to standard simultaneous lineup and showup procedures using receiver operating characteristic analysis. In terms of discriminability, the rate-them-all procedure was diagnostically inferior to both. A reasonable goal for future research is to make use of theoretical models of eyewitness identification to simultaneously maximize both discriminability and information gain. (PsycInfo Database Record (c) 2024 APA, all rights reserved).