Abstracts 2005 - The Psychonomic Society

Posters 3112–3119 Friday Evening
(3112)
Behavior Guiding Perception: The Visual, Verbal, and Haptic Reports
of Trained and Untrained Observers. ELIZABETH A.
CAMPBELL & DAVID L. CARPENTER, St. Bonaventure University—
Glider pilots, at some point, learn how to judge glide slope, yet it is
unclear exactly how this is learned. Research has shown different levels
of accuracy for different response modes in judging slopes. This
study attempted to determine which modality is the most accurate.
Another contradiction this study examined was that previous research
shows differing glide slopes at which individuals perform the most accurately.
Finally, it has been theorized that behavior causes perception,
rather than the reverse, which perceptual-matching tasks exemplify
and this study attempted to test. This study compared the judgment of
glide slope for untrained and trained observers, while also examining
the difference between three modes for responding: haptic (touch)
perceptual matching, visual perceptual matching, and verbal reports
of visual judgments for five glide slopes (25:1, 20:1, 12.5:1, 10:1,
5:1). It was determined that training has a significant effect on slope
only within the verbal condition at the optimal slope, the 12.5:1 slope.
(3113)
Sampling and Choice Under Competition for Resources. RUSSELL
C. BURNETT, YAAKOV KAREEV, & JUDITH AVRAHAMI, Hebrew
University of Jerusalem—In such diverse contexts as stock trading and
mate selection, choices are often made under competitive conditions
where collecting more information about options incurs higher risk of
losing desirable options to competitors. We examined how people approach
this tradeoff between goodness of evidence and availability of
options by having participants sample from urns containing different
proportions of winning chips. The first to stop sampling and select an
urn received payment based on the proportion of winning chips in that
urn, leaving the other participant to receive payment based on a remaining
urn. Preliminary findings include the following: (1) Competition
for resources led people to make large sacrifices in goodness of
evidence. (2) Nevertheless, people were not less confident in their decisions
under competition. (3) People exhibited a tendency to sample
from an urn that a competitor had not recently sampled from, apparently
seeking out private knowledge.
(3114)
Understanding Randomness: Errors of Judgment in the Generation
of Random Sequences. SUSAN F. BUTLER & RAYMOND S. NICK-
ERSON, Tufts University (sponsored by Raymond S. Nickerson)—The
generation of random sequences has been used as a means of demonstrating
participants’ misunderstandings of randomness. Critical criteria
for comparison were generated from both computer simulations
and actual flips of real coins. In either case, the sequences generated
by participants were significantly different from the critical criteria
for randomness generated by either the computer simulation or the
coin tosses.
(3115)
Optimal Predictions in Everyday Cognition. THOMAS L. GRIF-
FITHS, Brown University, & JOSHUA B. TENENBAUM, Massachusetts
Institute of Technology (sponsored by Joshua B. Tenenbaum)—
Human perception and memory are often explained as an optimal
statistical inference, informed by accurate prior probabilities. In contrast,
cognitive judgments are usually viewed as following error-prone
heuristics, insensitive to priors. We examined the optimality of human
cognition in a more realistic context than those in typical laboratory
studies, asking people to make predictions about the duration or extent
of everyday phenomena, such as human life spans, the box-office
take of movies, or how long they might wait for a bus. Our results suggest
that everyday cognitive judgments follow the same optimal statistical
principles as perception and memory and reveal a close correspondence
between people’s implicit probabilistic models and the
statistics of the world.
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(3116)
The Influence of Pre- Versus Postdecisional Advice on Likelihood
Estimates. DAVID G. SMITH, JOSEPH V. BARANSKI, MATTHEW J.
DUNCAN & DAVID R. MANDEL, Defence R&D Canada—When
making judgments in complex and ambiguous environments, people
often have the option of consulting an advisor. We report an experiment
examining how novices make judgments in a naval air threat assessment
simulation. On each trial, the participant integrates a series
of probabilistic cues in an attempt to determine the likelihood that an
aircraft is hostile (as opposed to friendly). We manipulated whether
advice is given before or after the participant’s initial judgment. Our
results demonstrate that advice has a stronger impact on the final
judgment if it is given after the participant’s initial judgment. We discuss
hypotheses as to why the timing of advice has a strong effect and
explore implications.
(3117)
The Comparison-to-the-Strongest Heuristic in the Frequency Format.
KUNINORI NAKAMURA & KIMIHIKO YAMAGISHI, Tokyo
Institute of Technology—Recent studies have revealed that probability
judgment is often sensitive to variations in how alternative outcomes
are distributed, even when such variation have no bearing on
the objective probability of the focal outcome. Windschitl and Wells
(1998) pointed out that people use the comparison-to-the-strongest
heuristic in probability judgment. In a typical task in these studies,
participants answered how they felt about their chances of winning the
gamble by single-event likelihood. This study investigated whether
people use the comparison-to-the-strongest heuristic when questions
of probability judgments are provided by frequency format (“If you
play this gamble 100 times, how often would you feel you win this
gamble?”). Participants estimated their winning probabilities of the
gamble, and the type of the question formats were manipulated (“If
you play this gamble 1 time/10 times/100 times”). The results indicated
that the use of frequency format reduced the use of the
comparison-to-the-strongest heuristics.
(3118)
Unbending the Inverse S-Shape: Testing an Adaptive Explanation
for Probability Weighting. JING QIAN & GORDON D. A. BROWN,
University of Warwick (sponsored by Evan Heit)—The probability
weighting function (PWF) in prospect theory (Kahneman & Tversky,
1979) has received considerable empirical support but, arguably, lacks
independent motivation. This paper offers an adaptive account for
probability weighting, suggesting that the observed PWF may reflect
the asymmetrical and bimodal distribution of probabilities encountered
in typical experiments and in the natural world. On the basis of
range frequency theory (Parducci, 1963, 1995), it is predicted that the
extent of the over- and underweighting of probabilities directly reflects
the density distribution of experienced contextual probabilities. In Experiment
1, this hypothesis is confirmed by modeling rated everyday
occurrence frequencies of 99 probabilities. In Experiment 2, we collected
subjective probabilities derived from a simple gambling experiment,
in which the probabilities were samples from a bimodal distribution
in one condition and from a unimodal distribution in another.
The results again support the hypothesis.
(3119)
Context-Specific Schemata Affect Judgments of Witness Credibility.
PAULA J. WADDILL, RICHARD ARLEDGE, & SHANNON MC-
BRIDE, Murray State University—Judgments of others’ emotional reactions
are influenced by the gender of the person displaying the emotion
and the context in which it is displayed. Women are expected to
be more emotional in interpersonal contexts, and men to be more
emotional in achievement contexts (Kelly & Hutson-Comeaux, 1999).
Furthermore, emotional display may result in negative sanctions if the
display is judged inappropriate in degree or form (the emotional doublebind;
Kelly & Hutson-Comeaux, 2000). In a set of two experiments,