Browsing by Author "Roeser, Jens"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Evaluating earwitness identification procedures: adapting pre-parade instructions and parade procedure
    (Taylor and Francis, 2022-10-06) Smith, Harriet; Roeser, Jens; Pautz, Nikolas; Davis, Josh P; Robson, Jeremy; Wright, David; Braber, Natalie; Stacey, Paula C.
    Voice identification parades can be unreliable, as earwitness responses are error-prone. In this paper we tested performance across serial and sequential procedures, and varied pre-parade instructions, with the aim of reducing errors. The participants heard a target voice and later attempted to identify it from a parade. In Experiment 1 they were either warned that the target may or may not be present (standard warning) or encouraged to consider responding “not present” because of the associated risk of a wrongful conviction (strong warning). Strong warnings prompted a conservative criterion shift, with participants less likely to make a positive identification regardless of whether the target was present. In contrast to previous findings, we found no statistically reliable difference in accuracy between serial and sequential parades. Experiment 2 ruled out a potential confound in Experiment 1. Taken together, our results suggest that adapting pre-parade instructions provides a simple way of reducing the risk of false identifications
  • No Thumbnail Available
    ItemOpen Access
    Voice parade procedures: Optimising witness performance
    (Taylor & Francis, 2019-10-08) Robson, Jeremy; Smith, Harriet; Braber, Natalie; Wright, David; Roeser, Jens; Stacey, Paula; Bird, Katherine
    Unfamiliar voice identification is error-prone. Whilst the investigation of system variables may indicate ways of boosting earwitness performance, this is an under-researched area. Two experiments were conducted to investigate how methods of presenting voices during a parade affect accuracy and self-rated confidence. In each experiment participants listened to a target voice, and were later asked to identify that voice from a nine-person target present or target absent parade. In Experiment 1, accuracy did not vary across parades comprising 15 or 30 s sample durations. Overall, when the target was present, participants correctly identified the target voice with 39% accuracy. However, when the target was absent, participants correctly rejected the parade 6% of the time. There was no relationship between accuracy and confidence. In Experiment 2, performance with a serial procedure, in which participants responded after hearing all nine voices, was compared with a sequential procedure, in which participants made a decision after listening to each voice. Overall accuracy was higher with the sequential procedure. These results highlight the importance of system variable research in voice identification. Different methods of presenting voices have the potential to support higher levels of accuracy than the procedure currently recommended in England and Wales.