Exploring the sequential lineup advantage using WITNESS.

Advocates claim that the sequential lineup is an improvement over simultaneous lineup procedures, but no formal (quantitatively specified) explanation exists for why it is better. The computational model WITNESS (Clark, Appl Cogn Psychol 17:629-654, 2003) was used to develop theoretical explanations for the sequential lineup advantage. In its current form, WITNESS produced a sequential advantage only by pairing conservative sequential choosing with liberal simultaneous choosing. However, this combination failed to approximate four extant experiments that exhibited large sequential advantages. Two of these experiments became the focus of our efforts because the data were uncontaminated by likely suspect position effects. Decision-based and memory-based modifications to WITNESS approximated the data and produced a sequential advantage. The next step is to evaluate the proposed explanations and modify public policy recommendations accordingly.

Robustness of the sequential lineup advantage.

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup advantages and 3 significant simultaneous advantages. Both sequential advantages occurred when the good photograph of the guilty suspect or either innocent suspect was in the fifth position in the sequential lineup; all 3 simultaneous advantages occurred when the poorer quality photograph of the guilty suspect or either innocent suspect was in the second position. Adjusting the statistical criterion to control for the multiple tests (.05/24) revealed no significant sequential advantages. Moreover, despite finding more conservative overall choosing for the sequential lineup, no support was found for the proposal that a sequential advantage was due to that conservative criterion shift. Unless lineups with particular characteristics predominate in the real world, there appears to be no strong preference for conducting lineups in either a sequential or a simultaneous manner. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Do prophylactics prevent inflation? Post-identification feedback and the effectiveness of procedures to protect against confidence-inflation in earwitnesses.

After viewing or hearing a recorded simulated crime, participants were asked to identify the offender's voice from a target-absent audio lineup. After making their voice identification, some participants were either given confirming feedback or no feedback. The feedback manipulation in experiment 1 led to higher ratings of participants' identification certainty, as well as higher ratings on retrospective confidence reports, in both the immediate and delay groups. Earwitnesses who were asked about their identification certainty prior to the feedback manipulation (experiment 2) did not demonstrate the typical confidence-inflation associated with confirming feedback if they were questioned about the witnessing experience immediately; however, the effects returned after a week-long retention interval. The implications for the differential forgetting and internal-cues hypotheses are discussed.

The mitigating effects of suspicion on post-identification feedback and on retrospective eyewitness memory.

Three studies examined procedures for reducing the post-identification feedback effect. After viewing a video event, participants were then asked to identify a suspect from a target-absent photo lineup. After making their identification, some participants were given information suggesting that their identification was correct, while others were given no information about the accuracy of their identification. Some participants who received confirming feedback were also given reasons to entertain suspicion regarding the motives of the lineup administrator, either immediately (Experiment 1) or after a one-week retention interval (Experiment 2). Suspicious perceivers failed to demonstrate the confidence inflation effects typically associated with confirming post-identification feedback. In Experiment 3, the confidence prophylactic effect was tested both immediately and after a one-week retention interval. The effect of confidence prophylactic varied with retention interval such that it eliminated the effects of post-identification feedback immediately but not after a retention interval. However, the suspicion manipulation eliminated the post-identification feedback effects at both time intervals. Both theoretical and practical implications are discussed.