Can a modified lineup procedure improve the usefulness of confidence?

In a face recognition, mini-lineup experiment we examined two aspects of the use of confidence about lineups. We modified the lineup procedure attempting to eliminate the difference in confidence–accuracy relationship between positive (old or identification) and negative (new or not present) decisions. In the modified procedure, participants: (1) selected the lineup member that best matched their memory of the target; (2) rated their confidence that the best match was indeed the target; and (3) indicated (yes/no) whether the best match was the target. Although the modified procedure produced higher accuracy than a standard simultaneous procedure, there was no evidence that it affected the confidence–accuracy relationship. Additionally, the modified procedure also allowed us to compare the extent to which confidence ratings versus binary recognition decisions better discriminated studied from unstudied faces. The results revealed a clear advantage for confidence, but indicated that binary responses were also a unique predictor.