Australasian Mathematical Psychology Conference 2019

Using the rank order task to estimate discriminability in eyewitness identification

Kym McCormick
School of Psychology, The University of Adelaide
Carolyn Semmler
The University of Adelaide
John C. Dunn
University of Western Australia

An ongoing debate within the field of eyewitness identification research centres on whether or not certain lineup procedures inhibit, or enhance, eyewitness memory. The assessment of a procedure’s effectiveness requires the estimation of an eyewitnesses ability to discriminate between a target and the foils within a lineup ($d’$). Traditionally, this has been done through simple ROC analysis, such as measuring the area under the curve, which is problematic and often requires the fitting of empirical data to a mathematical model of behaviour, such as signal detection theory. However, such fitting of lineup data also necessitates the modelling of decision processes (e.g. Independent-Observations model, Integration model, Ensemble model etc.), about which there is currently very little agreement (see Wixted, J. T., Vul, E., Mickes, L., & Wilson, B. M. (2018). Models of Lineup Memory. Cognitive Psychology. 105, 81-114.). This presentation will introduce a novel eyewitness identification task—Rank-Order task—which eliminates the need to model such decision processes and allows for the estimation of a baseline $d^\prime$, from which to assess binary eyewitness identification task presentations.