“Only your first yes will count”: The impact of prelineup instructions on sequential lineup decisions.

Abstract

When administering sequential lineups, researchers often inform their participants that only their first yes response will count. This instruction differs from the original sequential lineup protocol and from how sequential lineups are conducted in practice. Participants (N = 896) viewed a videotaped mock crime and viewed a simultaneous lineup, a sequential lineup with a first-yes-counts instruction, or a sequential control lineup (with no first-yes-counts instruction); the lineup was either target-present or target-absent. Participants in the first-yescounts condition were less likely to identify the suspect and more likely to reject the lineup than participants in the simultaneous and sequential control conditions, suggesting a conservative criterion shift. The diagnostic value of suspect identifications, as measured by partial Area Under the Curve, was lower in the first-yes-counts lineup than in the simultaneous lineup. Results were qualitatively similar for other metrics of diagnosticity, though the differences were not statistically significant. Differences between the simultaneous and sequential control lineups were negligible on all outcomes. The first-yescounts instruction undermines sequential lineup performance and produces an artefactual simultaneous lineup advantage. Researchers should adhere to sequential lineup protocols that maximize diagnosticity and that would feasibly be implemented in practice, allowing them to draw more generalizable conclusions from their data.

Experimental validation of a multinomial processing tree model for analyzing eyewitness identification decisions

“…A superiority of sequential lineups has been postulated based on the diagnosticity ratio 44 which, however, has been criticized for confounding the ability to distinguish between a culprit and an innocent suspect and response bias 20 . SDT-based analyses have sometimes shown equivalent performance of simultaneous and sequential lineups 13 , 37 , 39 , 47 , 83 , 84 and sometimes a superiority of simultaneous over sequential lineups 11 , 38 , 62 , 85 – 88 . In all experiments reported here, the estimates of the culprit-presence detection parameter dP were slightly but consistently higher in the simultaneous-lineup conditions than in the sequential-lineup conditions.…”

“…By contrast, in many previous studies the only-the-first-yes-counts rule was used. Horry et al 62 have demonstrated that only-the-first-yes-counts instructions systematically reduce the rate of positive identifications in sequential lineups by discouraging participants from guessing. This is plausible at a psychological level: participants may well shy away from using their only identification option when they cannot know, at the time of their decision, whether better options will follow.…”

A meta-analysis of lineup size effects on eyewitness identification.

“…Meissner et al (2005) reported a decrease in diagnosticity as more fillers are added to a lineup; however, they did not detect an interaction with the mode of lineup presentation. These conflicting findings may have been a consequence of how the sequential lineups were operationalized in the experiments, as the methodologies were all quite different and there are many sequential lineup features that could interact with lineup size, such as the prelineup instructions, the suspect’s position, and the stopping rule (Horry et al, 2020; Steblay et al 2011).…”

Identifying unfamiliar voices: the influence of sample duration and parade size.

“…Another explanation may be that there is, as argued by Horry et al (2021), a dynamic criterion shift which reduces the conservative criterion of listeners as the parade progresses.…”