David Emmett1 THE VIRTUAL LICENCE PLATE (VLP) AND ITS EFFECT ON EYEWITNESS PERFORMANCE An update on ongoing research David Emmett, Brian R. Clifford, Kelly Young, Margarita Kandova, & Anita Potton

David Emmett2 The problem “Eyewitness recall of a licence plate can be the backbone for case solutions.” MacKinnon, O’Reilly & Geiselman (1990) “In events such as hit and run accidents the time available for viewing the licence plate is often between 0.2 and 5 seconds.” Al-Haboubi (1999) “Witness reports are often incomplete distorted or inaccurate.” Fisher & Geiselman (1992)

David Emmett3 The potential With licence plate details now computerised in most countries, vehicle owner searches can be carried out with great speed even on partial details. Clearly, however, the more licence plate characters that a witness correctly recalls then the greater is the chance that a vehicle owner can be successfully traced.

David Emmett4 Previous research Despite the potential importance of licence plate recall to criminal investigations, a search of the extant eyewitness literature prior to the commencement of this series of studies, reveals almost a complete lack of research into either the ability of eyewitnesses to accurately recall the details of vehicle licence plates or ways in which such recall can be assisted

David Emmett5 MacKinnon, O’Reilly & Geiselman (1990) In a study using a series of still slides as stimuli in which a 7 character Californian licence plate was visible from various distances and with varying clarity for a total of 45 seconds together with immediate recall. A control group correctly recalled 3.15 characters.

David Emmett6 A second group, using a simulated licence plate made from coloured cardboard with removable vinyl alphanumeric characters, achieved a non significant 7% increase in characters recalled. A third group, using the plate simulator and the context reinstatement mnemonics of the cognitive interview, achieved a significant increase of 22% in correct character recall MacKinnon, O’Reilly & Geiselman (1990)

David Emmett7 The current series of studies A 21 st century approach The Virtual Licence Plate (VLP) An electronic version of MacKinnon, O’Reilly & Geiselman’s cardboard simulator

David Emmett8 Brief history of this research Early studies in this series concentrated on testing the efficacy of the concept of using a Virtual Licence Plate as a memory retrieval aid and then developing the VLP to its maximum efficiency. Significant improvement in eyewitness recall of licence plates was seen using the VLP, especially in conjunction with Mental Context Reinstatement. The results of two early studies using VLP v.1 and v.2 were reported in Emmett, D., Clifford, B. R., Young, K., & Potton, A. (2004).

David Emmett9 Present state of the research During the initial studies it was clear that the use of the VLP in conjunction with MCR was having a beneficial effect on the recall of details of the crime scene beyond the licence plate Testing needed to be carried out using both the ‘old’ and ‘new’ style UK licence plates. Would similar results be seen?

David Emmett10 The current studies Two studies are presented Both use VLP v.2 and MCR Recall of licence plate and general crime scene details tested Old and new style UK licence plates

David Emmett11 A brief introduction to VLP v.2

David Emmett12 VLP v.2

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David Emmett16 ‘New’ and ‘Old’ style plates ‘OLD’ ‘NEW’

David Emmett17 Experiment 1 Stimulus Video of staged child abduction with ‘old style’ licence plate clearly visible for 3 seconds watched as individuals Participants 104 undergraduates – naïve as to reason for watching video

David Emmett18 Experiment 1 Delay 5 minutes – filled with Ravens Matrices to prevent rehearsal Recall 4 conditions – each conducted individually Control – pencil and paper recall VLP only – experimenter operated use of VLP MCR only – individual MCR instructions VLP + MCR – above two conditions in combination

David Emmett19 Dependent Variables Alphanumeric licence plate character correctly recall in the correct location Correctly recalled details of the crime scene, other than the licence plate, through cued recall Errors are not being included in this presentation

David Emmett20 Licence plate characters group Characters correctly recalled Significance compared to control control3.35 VLP4.12p > 0.05 MCR4.62p < 0.05 VLP + MCR 5.65p < – 4 characters correctly recalled 5 -7 characters correctly recalled Control57.7%42.3% VLP53.8%46.2% MCR50.0% VLP + MCR11.5%88.5%

David Emmett21 Recall of crime scene details group Items of information correctly recalled Significance compared to control control25.08 VLP25.92p > 0.05 MCR31.92p < 0.05 VLP + MCR37.65p < 0.001

David Emmett22 Experiment 2 Stimulus Video of staged street arrest with ‘new style’ licence plate clearly visible for 5 seconds watched as individuals Participants 48 undergraduates – naïve as to reason for watching video

David Emmett23 Delay 5 minutes – filled with Ravens Matrices to prevent rehearsal Recall 3 conditions – each conducted individually Control – pencil and paper recall MCR only – individual MCR instructions VLP + MCR – above two conditions in combination Dependent Variables - as before Experiment 2

David Emmett24 Licence plate characters group Characters correctly recalled Significance compared to control control2.81 MCR4.94p < 0.01 VLP + MCR 6.31p < – 4 characters correctly recalled 5 -7 characters correctly recalled Control87.5%12.5% MCR31.3%68.7% VLP + MCR12.5%87.5%

David Emmett25 Recall of crime scene details group Items of information correctly recalled Significance compared to control control23.38 MCR29.06p < 0.05 VLP + MCR35.63p < 0.001

David Emmett26 Discussion licence plate details Clearly in both experiments the use of the VLP and particularly the use of the VLP in combination with MCR has led to a marked increase in licence plate recall. In the case of the VLP plus MCR combination this increase was significant in both experiments Experiment 1- increase of 2.30 characters Experiment 2 - increase of 3.50 characters

David Emmett27 Mental Context Reinstatement Based upon the MCR mnemonic of the Cognitive Interview Witness mentally reinstates the context of the to- be-remembered event. Technique applied with great care and intensity. Encoding Specificity Hypothesis/Principle (Tulving, 1976; 1983; Tulving & Thompson, 1973)

David Emmett28 Increase in contextual cues that enable the witness to bring to life their encoded memory trace. This is particularly true of the characters that the witness adds to the plate. Each character acting as a powerful cue to the next. Encouragement of witness to concentrate and consider different ‘candidate combinations’ of characters. VLP v.2

David Emmett29 Part recognition task – Initial retrieval is a recall task but then VLP provides a solid manifestation of that recall enabling the witness to compare it directly with the encoded trace in a recognition-like process. Allows witness to access the power of the ‘change order’ mnemonic of the CI. VLP v.2

David Emmett30 Clear that there is an additive if not multiplicative effect when using VLP with MCR MCR requires witnesses to focus on the target licence plate and form a mental image of it. The VLP enables the witness to bring that mental image into concrete existence, to examine it, and through a process of comparison with the encoded trace refine it until as close a match as possible is achieved. + MCR

David Emmett31 Clearly in both experiments the use of the VLP in combination with MCR has led to a marked increase in the recall of crime scene details other than the licence plate. This increase was significant in both experiments Experiment 1- increase of 50.1% Experiment 2 - increase of 52.4% Recall of crime scene details

David Emmett32 Mental Context Reinstatement The strongest effects are typically found in free recall, with less strong effects in cued recall Technique applied with great care and intensity. Increases with MCR alone Experiment 1- increase of 27.3% Experiment 2 - increase of 24.3% VLP v.2 Makes little apparent contribution on its own Experiment 1- increase of 3.3%

David Emmett33 + MCR Clearly, as with the licence plate details there is an additive if not multiplicative effect on general crime scene recall when using VLP with MCR How does a technique designed to improve recall of licence plates also exerts a highly beneficial effect on the recall of details of the event of which the licence plate forms a part?

David Emmett34 The witnesses’ mind is focussed sharply onto both the licence plate and the events that surround it. Increased interaction between witness and experimenter leads to increased feelings of involvement and motivation + MCR

David Emmett35 Next steps Combining MCR with the VLP not only offers investigators a powerful practical tool to assist eyewitnesses in the recall a target licence plate but also details of the event within which the licence plate is embedded. We now feel that the time is right to move out of the lab and into live trials with the Police service

David Emmett36 Last question What was the licence plate that you saw at the beginning?