Steblay, N., Dysart, J., Fulero, S., & Lindsay, R. C. L. (2001). Eyewitness accuracy rates in sequential and simultaneous lineup presentations: A meta-analytic comparison. Law and Human Behavior, 25, 459-473.
The authors discuss the sequential superiority effect, and sequential lineups producing fewer mistaken identifications compared to simultaneous lineups. This article is a meta-analysis of research involving simultaneous and sequential lineups. The meta-analysis included data from 23 papers, but many of the studies were unpublished and from a single laboratory. First, they examined correct identifications across both target-present and target-absent lineups and found that sequential lineups produced more correct decisions than simultaneous lineups. They then separated lineups into target-present and target-absent to examine accuracy rates.
Their main finding was that simultaneous lineups produce more correct identifications in target-present lineups, whereas sequential lineups produce more correct rejections in target-absent lineups. This finding means that the sequential lineup reduces false identification errors. These findings are discussed in terms of relative and absolute judgments in lineup administration, with simultaneous lineups allowing for more relative judgments, and sequential lineups allowing for more absolute judgments. Identification accuracy of choosers, participants who make a choice when viewing a lineup, was also examined. Simultaneous lineups tended to have higher choosing rates as compared to sequential lineups. The authors also examined a variety of moderator variables, the strongest of which was verbal descriptions. Verbal descriptions prior to lineup administration tended to eliminate the advantage of the simultaneous lineup for correct identifications.
The overall results indicated that the sequential superiority effect was supported. The issue of relative judgments was discussed because simultaneous lineups produce higher correct identifications, and this finding can be explained with the idea that participants are comparing lineup members to each other. However, absolute judgments of comparing each photograph individually to the participant's memory are believed to underlie sequential lineups. Correct identifications from simultaneous lineups are also discussed in terms of policy implications for police departments. The authors reason that simultaneous lineups lead participants to choose more in lineups, and this choosing may result in possibly correct guessing, which may be a potential problem in eyewitness identification.
By HC
In reference to the Steblay/Dysart article, I thought the information regarding the identification accuracy of choosers in sequential and simultaneous lineups. When considering "choosers" in either a target-present or target-absent lineup, the simultaneous lineup causes at least a 20% higher number of people making a choice than the sequential lineup. The article does a great job of explaining the overall significance of a higher rate of "choosers" in simultaneous vs. sequential lineup method. Participants in a sequential lineup are less likely to make a lineup choice, so when the perpetrator is present the lower choosing rate results in false rejection errors, but the errors committed in this style are mostly of rejecting the lineup all together. In a target-absent lineup, the participant's caution in choosing (hesitation), due to a sequential lineup, assists in making a more accurate decision. I enjoyed your topic presentation.
Upon reading the article by Steblay et al. (2001), I learned a lot more about the difference between simultaneous and sequential lineups. According to their research, simultaneous lineups were the most commonly procedure used by police officers. It is good that there is lots of research being done on this topic to discredit the simultaneous lineup because it is not the best. The sequential lineup has shown to be the better candidate.
A simultaneous lineup is wheat you see in the movies. A group of 6-8 people walk into a room and the witness uses their “relative judgment” on who most closely resembles the perpetrator (Steblay et al., 2001). This article used meta-analysis on over twenty-three papers. Nine of the papers were published and fourteen were not published. I was not quite sure what meta-analysis was at first, but I thought it just compared research data to come to a conclusion about the hypothesis. I searched the definition of meta-analysis and I was actually pretty close. An operational definition of meta-analysis would have been nice, but it is probably common knowledge.
Wells and Lindsay (1985), developed a new lineup procedure that we know as the sequential lineup. This procedure has the witness view suspects one by one. Witnesses are not able to look at the next suspect before deciding if the current one is the perpetrator. This cuts down on relative judgment and leads the witness to use absolute criterion. This in affect reduces false identification rates. When the perpetrator is present, simultaneous and sequential have the same identification rates and when the perpetrator is not present, 43% misidentified the perpetrator in simultaneous lineups and only 17% with sequential. The sequential superiority has been replicated in experiments all over the world. I enjoyed this article because the writing style was very precise and easy to read.