The role of metamemory in eyewitness testimony performamce

Student thesis: Doctoral Thesis


Estimating eyewitness memory accuracy is crucial in forensic settings, given the need for efficient investigations and the negative consequences of erroneous testimony. In this thesis, the overarching goal of the research was to test the utility of metamemory assessments as postdictors of eyewitness performance. Metamemory research is essential for a comprehensive understanding of how people use and perceive their own memory, but it has not yet been thoroughly explored in eyewitness settings. In the initial experiments (Experiments 1 and 2), the relationship between self-reports of memory ability and eyewitness identification performance was examined. Specifically, we tested how self-ratings of memory ability and strategies endorsement relate to eyewitness identification accuracy, confidence and over/underconfidence. These experiments provided initial evidence that some metamemory factors are important indicators of eyewitness identification accuracy and confidence, although only assessments of global memory self-efficacy were adopted. Aiming to improve metamemory assessments in eyewitness contexts, a measure tailored specifically to eyewitness testimony settings was developed and tested in Experiment 3) In Experiment 4, the predictive value of general and eyewitness-specific metamemory assessments (EMS) on identification performance for biased and unbiased lineups was investigated. We were specifically interested in possible differential effects between biased and unbiased lineups because other postdictors of identification performance have less diagnostic value in biased lineups. The results of Experiment 4 showed that eyewitness-specific metamemory factors are predictive of identification accuracy for both biased and unbiased lineups. In Experiment 5 an innovative repeated-trials eyewitness identification paradigm was used to examine the relation between metamemory assessments and identification performance, obtaining further evidence for a relation between eyewitness-specific metamemory factors and identification performance. In the final experiment (Experiment 6), the focus is shifted from identification paradigms to an eyewitness free recall paradigm, aiming to elucidate the relation between metamemory and disclosure of information. We summarize the main findings of this novel line of research in the General Discussion, presenting the challenges and prospects facing future eyewitness metamemory research.
Date of AwardJul 2019
Original languageEnglish
Awarding Institution
  • University of Portsmouth
SupervisorLorraine Hope (Supervisor)

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