Abstracts 2005 - The Psychonomic Society

Sunday Morning Papers 328–330
11:00–11:15 (328)
Decision Strategies and Criterion Shifts in Eyewitness Identification.
STEVEN E. CLARK, SHERRIE DAVEY, & RYAN GODFREY, University
of California, Riverside—One of the concerns about eyewitness
identification is that witnesses may feel pressure to make an identification,
even when they are not sure. The present research addresses
two main questions: First, why do witnesses hesitate to make an identification?
Is their hesitation due to poorer memory or a higher criterion,
relative to witnesses who do make identifications? Second, when
reluctant witnesses are nudged into making identifications, do they
simply lower their decision criterion or do they change their decision
strategies in more fundamental ways? To address these two questions,
we reanalyzed a previous meta-analysis (Steblay, 1997) that appeared
to rule out a criterion shift explanation and also conducted three new
studies in which the specifics varied as to how participants were
nudged. Our results did not support the “bad memory” view of the reluctant
witness. Whether participants lower their criterion or change
their strategy depends on the specifics of the pre-lineup instructions.
11:20–11:35 (329)
A Signal Detection Model of Eyewitness Identification. MATTHEW
J. DUNCAN, Defence R&D Canada—Procedurally, an eyewitness identification
task is a case of uncertain detection plus identification. Although
much has been done to examine the effect of various pretest
factors, development of formal mathematical models seems noticeably
absent. This is unfortunate, because the nature of the eyewitness
identification task is one in which sensitivity and bias are potentially
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confounded. Monte Carlo simulations and formal analysis of Clark’s
(2003) WITNESS model showed it to conform to normal distribution
assumptions and an uncertain detection plus identification framework.
Consequently, a detection plus identification SDT model was
developed and fit to data from a number of experiments. A variety of
detection and identification decision rules were assessed, and the fit
of the model was compared with simulations of WITNESS.
11:40–11:55 (330)
Misinformation Effects in Product Identification Testimony.
J. TRENT TERRELL & CHARLES A. WEAVER III, Baylor University
(read by Charles A. Weaver III)—Although research on the reliability
of eyewitness memory for criminal events has been extensively
studied, eyewitness memory in civil cases has not. We have developed
a paradigm with which to study memory for product identification, a
common question in civil cases involving product liability. Subjects
were shown a videotaped cooking show and later were asked to identify
the specific brands of products used. Subjects given intentional
memory instructions were more accurate initially, but not after a delay.
In a second experiment, misinformation regarding a brand was introduced
in incidental questioning. One week later, subjects were more
likely to select the suggested brand than the brand actually used. This
was especially true for familiar items: When the suggested brands were
highly familiar (but still wrong), false alarm rates were nearly 70%.
Furthermore, these false alarms to suggested items were recalled with
greater subjective confidence, indicating an inverse confidence–accuracy
relationship.