Confidence and accuracy of lineup selections and rejections: Postdicting rejection accuracy with confidence

Improving the diagnostic value of lineup rejections

Erroneous eyewitness identification evidence is likely the leading cause of wrongful convictions. To minimize this error, scientists recommend collecting confidence. Research shows that eyewitness confidence and accuracy are strongly related when an eyewitness identifies someone from an initial and properly administered lineup. However, confidence is far less informative of accuracy when an eyewitness identifies no one and rejects the lineup instead. In this study, I aimed to improve the confidence-accuracy relationship for lineup rejections in two ways. First, I aimed to find the lineup that yields the strongest confidence-accuracy relationship for lineup rejections by comparing the standard, simultaneous procedure used by police worldwide to the novel "reveal" procedure designed by scientists to boost accuracy. Second, I aimed to find the best method for collecting confidence. To achieve this secondary aim, I made use of machine-learning techniques to compare confidence expressed in words to numeric confidence ratings. First, I find a significantly stronger confidence-accuracy relationship for lineup rejections in the reveal than in the standard procedure regardless of the method used to collect confidence. Second, I find that confidence expressed in words captures unique diagnostic information about the likely accuracy of a lineup rejection separate from the diagnostic information captured by numeric confidence ratings. These results inform models of recognition memory and may improve the criminal-legal system by increasing the diagnostic value of a lineup rejection.

New Insights on Expert Opinion About Eyewitness Memory Research

Experimental psychologists investigating eyewitness memory have periodically gathered their thoughts on a variety of eyewitness memory phenomena. Courts and other stakeholders of eyewitness research rely on the expert opinions reflected in these surveys to make informed decisions. However, the last survey of this sort was published more than 20 years ago, and the science of eyewitness memory has developed since that time. Stakeholders need a current database of expert opinions to make informed decisions. In this article, we provide that update. We surveyed 76 scientists for their opinions on eyewitness memory phenomena. We compared these current expert opinions to expert opinions from the past several decades. We found that experts today share many of the same opinions as experts in the past and have more nuanced thoughts about two issues. Experts in the past endorsed the idea that confidence is weakly related to accuracy, but experts today acknowledge the potential diagnostic value of initial confidence collected from a properly administered lineup. In addition, experts in the past may have favored sequential over simultaneous lineup presentation, but experts today are divided on this issue. We believe this new survey will prove useful to the court and to other stakeholders of eyewitness research.

Comparing Younger and Older Adult Eyewitnesses: Examining the Simultaneous, Elimination, and Wildcard Lineup Procedures

Older adults (60- to 99-year-olds) and younger adults (18- to 49-year-olds) viewed a videotaped theft and were then asked to provide a description of the perpetrator. Following a brief delay, participants were presented with a simultaneous, elimination, or wildcard lineup procedure that was either target-present or target-absent. Overall, younger adult eyewitnesses were more likely to be correct in their identification decisions, reported more perpetrator descriptors, and had a higher proportion of accurate descriptors compared to older adults. Moreover, the simultaneous and elimination procedures were superior to the wildcard procedure in target-absent lineups. When presented with a target-present lineup, participants were more likely to be correct when presented with the simultaneous procedure compared to the elimination procedure. Neither of the identification procedures that have been shown to be beneficial with child eyewitnesses appear to have influenced the rate of correct identification or correct rejection for older adults as a separate age group.