Sl. Sporer, POST-DICTING EYEWITNESS ACCURACY - CONFIDENCE, DECISION-TIMES AND PERSON DESCRIPTIONS OF CHOOSERS AND NON-CHOOSERS, European journal of social psychology, 22(2), 1992, pp. 157-180
This study sought to investigate the utility of several variables to p
ost-dict eyewitness identification accuracy in target-present and targ
et-absent line-ups in a staged-event paradigm. The incident involved a
nd altercation between an experimenter and a confederate who attempted
to take away the slide projector needed for an ongoing laboratory exp
eriment. Sixty-two subject-witnesses were called back to the laborator
y one week after the incident, purportedly to answer some additional q
uestions about the laboratory experiment. They were asked to provide a
description of the intruder and to indicate whether or not they thoug
h they would be able to identify the target (pre-decision confidence).
Next, they saw a video line-up with or without the target present. Us
ing choice of a line-up member as a mediating variable, with choosers
post-decision confidence (r = 0.58) and decision-time (r = -0.43) were
strongly related to the accuracy of this choice while pre-decision co
nfidence was not. For non-choosers, no meaningful relationship between
these variables and identification accuracy was observed. There was a
lso some evidence that the number of descriptors was significantly rel
ated to identification accuracy (r = 0.28). Results are discussed in t
erms of the importance of choice as a mediating variable for post-dict
ing identification decisions in studies using both target-present and
target-absent line-ups. Forensic implications of confidence and decisi
on-time as verbal and non-verbal indicators for the post-hoc assessmen
t of identification accuracy are stressed.