Problem solving in judgment under uncertainty.

This article presents a problem-solving approach to judgment under uncertainty. According to this approach, the application of statistical rules and nonstatistical rules depends on the same general problem-solving factors. The experiments reported herein used base-rate problems to study four such factors: the prior and immediate activation of the rules, their relation to the goal, and their applicability to the givens of the problem. All of the experiments used purely statistical base rates and highly representative case information. Supporting the prior activation assumption, Experiment 1 found that prior use of base rates enhanced subsequent use of other base rates. Consistent with the immediate activation assumption, Experiment 2 showed that the use of base rate increased with their immediate salience. Experiments 3 and 4 demonstrated that the application of inferential rules is goal driven. Specifically, base-rate and case information were used to the extent that they led to satisfactory solutions. Finally, Experiments 5 and 6 demonstrated subjects' sensitivity to restrictions on the application of the relevant statistical and nonstatistical rules. In these experiments, subjects' reliance on base rates increased with the perceived randomness of the process whereby the case was selected from the population and with the perceived unreliability of the source of case information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Between ignorance and truth: Partition dependence and learning in judgment under uncertainty.

In 3 studies, participants viewed sequences of multiattribute objects (e.g., colored shapes) appearing with varying frequencies and judged the likelihood of the attributes of those objects. Judged probabilities reflected a compromise between (a) the frequency with which each attribute appeared and (b) the ignorance prior probability cued by the number of distinct values that the focal attribute could take on. Thus, judged probabilities were partition dependent, varying with the number of events into which the state space was subjectively divided. This bias was diminished among participants more confident in what they learned, was strong and insensitive to level of confidence when ignorance priors were especially salient, and required ignorance priors to be salient only when probabilities were elicited (not during encoding). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of short-term memory capacity and task experience for overconfidence in judgment under uncertainty.

Research with general knowledge items demonstrates extreme overconfidence when people estimate confidence intervals for unknown quantities, but close to zero overconfidence when the same intervals are assessed by probability judgment. In 3 experiments, the authors investigated if the overconfidence specific to confidence intervals derives from limited task experience or from short-term memory limitations. As predicted by the naive sampling model (P. Juslin, A. Winman, & P. Hansson, 2007), overconfidence with probability judgment is rapidly reduced by additional task experience, whereas overconfidence with intuitive confidence intervals is minimally affected even by extensive task experience. In contrast to the minor bias with probability judgment, the extreme overconfidence bias with intuitive confidence intervals is correlated with short-term memory capacity. The proposed interpretation is that increased task experience is not sufficient to cure the overconfidence with confidence intervals because it stems from short-term memory limitations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individuation, counting, and statistical inference: The role of frequency and whole-object representations in judgment under uncertainty.

Evolutionary approaches to judgment under uncertainty have led to new data showing that untutored subjects reliably produce judgments that conform to many principles of probability theory when (a) they are asked to compute a frequency instead of the probability of a single event and (b) the relevant information is expressed as frequencies. But are the frequency-computation systems implicated in these experiments better at operating over some kinds of input than others? Principles of object perception and principles of adaptive design led us to propose the individuation hypothesis: that these systems are designed to produce well-calibrated statistical inferences when they operate over representations of "whole" objects, events, and locations. In a series of experiments on Bayesian reasoning, we show that human performance can be systematically improved or degraded by varying whether a correct solution requires one to compute hit and false-alarm rates over "natural" units, such as whole objects, as opposed to inseparable aspects, views, and other parsings that violate evolved principles of object construal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An informational analysis of clinical judgment.

Information theory was used as a theoretical model and methodological tool for the study of certain aspects of the clinical judgment process. By means of such a model, the capacity of a group of clinicians to process case information was studied. 3 types of input conditions were systematically varied with 3 types of judgments. It was found that the number of discriminations made by each group was close to the maximum of 3.00 bits, although the number of reliable discriminations was more limited, ranging from .88 to 1.49 bits. An increase in reliable discriminations as a consequence of adding more case information was rather slight. The 3 judgment systems were found to be highly interrelated, suggesting a common underlying response dimension. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysical judgment: electro-cortical and heart rate correlates of accuracy and uncertainty

The relationship between perceptual accuracy and physiological response amplitude was investigated in an auditory pitch discrimination experiment. Confidence ratings were obtained from all subjects following each trial. The stimulus set consisted of three tones of different frequencies spaced in a manner to provide both easy and difficult discriminations. Heart rate, EEG and vertical eye movement were recorded throughout the experiment. The results of the experiment indicated that the largest evoked cardiac rate response was elicited by the stimulus which produced the fewest errors in judgment; larger auditory evoked potentials, particularly the late positive component (P300), were associated with the 'easy' stimulus; greater cortical negativity was associated with the difficult stimuli. Eye activity was found to covary with judgmental accuracy; cortical slow wave activity was particularly sensitive to the confidence, or 'uncertainty' parameter. A 'decision tree' model was hypothesized to describe the processing mechanism involved in solving the discrimination problem.     

An investigation of clinical judgment: A study in method.

To investigate the accuracy of judgment in the use of cues in a perceptual discrimination task, 2 sets of cards were constructed: 1 where the relevant cue was color; the other, size. Ss were required to identify the cue dimension. Some Ss were given prior training in cue-identification, some not. In a 2nd reported experiment a spatial task was constructed. Ss had to make judgments and predict how other Ss would perform on a task after receiving certain information about them. Both experiments intended to explore the nature of the judgmental process as it may be understood from a laboratory experiment, and in both, accuracy of judgment was improved when the judge could use more than 1 cue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distributive judgments under uncertainty: Paccioli's game revisited.

Many decision biases arise from the inability to ignore past events. The coherence of decisions is also compromised by the inability to fully use information related to the future. In Paccioli's game, a stake of money goes to the first player to score a certain number of wins. When the game is prematurely interrupted, they may divide the stake according to the proportions of wins relative to rounds played. Alternatively, they may assess the probability that a player would reach the criterion number of wins first if the game were continued. The first decision rule (ratio), which is past-oriented, leads to contradictions across games. The second rule (probability), which is future-oriented, does not. In seven studies, use of the ratio rule emerges across testing methods, in games of chance and games of skill, and independently of extraneous factors (such as random responding, lack of awareness, or proneness to other past-oriented biases). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thurstonian and Brunswikian origins of uncertainty in judgment: A sampling model of confidence in sensory discrimination.

As a preliminary step towards the presentation of a model of confidence in sensory discrimination, the authors propose a distinction between 2 different origins of uncertainty named after 2 of the great probabilists in the history of psychology, L. L. Thurstone and Egon Brunswik. The authors review data that suggest that there are empirical as well as conceptual differences between the 2 modes of uncertainty and thus that separate models of confidence are needed in tasks dominated by Thurstonian and Brunswikian uncertainty. The article presents a computational model for 1 class of tasks dominated by Thurstonian uncertainty: sensory discrimination with pair comparisons. The sensory sampling model predicts decisions, confidence assessments, and the complex pattern of response times in simple psychophysical discrimination tasks (J. V. Baranski and W. M. Petrusic, 1994). The model also accounts for the disposition towards underconfidence often observed in sensory discrimination with pair comparisons (M. Bjorkman, P. Juslin, & A. Winman, 1993; C. S. Peirce & J. Jastrow, 1884). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Contrast effects in attitude judgment: An examination of the accentuation hypothesis.

A common finding in attitude judgment is that attitude positions discrepant from an extreme judge's own position are judged as more discrepant than in fact they are. The 2 studies in this article suggest that these contrast effects may be due to accentuation phenomena, as outlined by H. Tajfel (see record 1958-04920-001). Judges may make more polarized pro/anti judgments if they perceive the attitude positions as also differing on an agree/disagree (peripheral) dimension and if the judgment dimension and the peripheral dimension are correlated. In Study 1, a survey was conducted of 290 members of the National Organization for Women and the Massachusetts Federation of Republican Women to test the hypothesis. Strong support was found for the accentuation explanation of contrast effects. To rule out an individual difference alternative explanation for these results, Study 2 with 44 undergraduates experimentally manipulated the salience of the agree/disagree peripheral dimension. Greater contrast was found when the dimension was salient. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Four techniques of group decision making under uncertainty.

4 techniques of group decision-making—authoritarian, leader suggestion, census, and chairman—under risk and uncertainty were compared using a survival situation with 45 aircrews. "1. In a conflict situation, when a group discussion method… is involved, the members' reactions to the alternatives are relatively undifferentiated in contrast to the condition in which the leader alone makes the decision… . 2… . the groups appear to be least favorably disposed toward the authoritarian technique of decision-making… . 3. When the decision-making procedure is group centered the group reaches a decision involving greater personal risk to the members." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognizing: The judgment of previous occurrence.

Several suggestions for a class of theories of recognition memory have been proposed during the past decade. These models address predictions about judgments of prior occurrence of an event, not the identification of what it is. The history and current status of one of these models is discussed. The model postulates the detection of familiarity and the utilization of retrieval mechanisms as additive and separate processes. The phenomenal experience of familiarity is assigned to intraevent organizational integrative processes; retrieval depends on interevent elaborative processes. Other current theoretical options are described, and relevant supportive data from the literature are reviewed. New tests of the model involving both free recall and word pair paradigms are presented. The dual process model is extended to the word frequency effect and to the recognition difficulties of amnesic patients. (68 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When discounting fails: Conditions under which individuals use discredited information in making a judgment.

Investigated in 2 experiments the conditions that promote successful discounting of knowledge in making a judgment. 122 (Exp I) and 155 (Exp II) undergraduate students first learned a set of arguments describing a person. Later, they were told to use a subset of these arguments to judge the person. This was done in 1 of 2 ways. Half of the Ss received instructions specifying the subset of arguments that were actually to be used in the judgment. For the other half, the supplementary subset was specified; that is, they were told which of the arguments were to be ignored. As a result, in the latter condition the to-be-ignored arguments were salient, whereas in the former condition the to-be-used arguments were salient. Results of both experiments indicate that discounting was most successful when the to-be-ignored arguments were salient. Orthogonally to the salience manipulation, the experiments varied the extent to which the arguments were integrated before discounting. Exp II demonstrated that discounting fails when arguments are represented in an integrative rather than a discrete manner. Implications of these findings for theories of discounting are discussed. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical judgment under varied informational conditions: Rorschach, personal data, and best guess.

Requested 105 psychological clinicians to make clinical judgments derived from Rorschach information and personal history data (RPD), personal history data alone (PD), or best guesses (BG) on diagnosis, anxiety, and intelligence. Compared with the BG group, the RPD group was significantly more accurate on anxiety and the PD group on diagnosis (p     

Concentrator utilisation under geological uncertainty

Mineral concentrators are designed from preliminary geological data, and are therefore subject to geological uncertainty. This uncertainty has a demonstrable impact on the mining lifecycle, and has motivated stochastic strategic mine planning algorithms. The current paper describes how these algorithms may be extended to consider mineral processing operations in conjunction with open-pit mining operations. In particular, the paper describes an effective way to incorporate variable concentrator feed grade into these algorithms, which is the first step toward more elaborate representations of mineral concentrators. The resulting framework will be able to connect geological data to alternate configurations of the downstream resources, hence comparing the benefit of each configuration, and the corresponding capital investments. Sample computations are presented, comparing the net present value and utilisation for several different mineral processing capacities.     

Quality of group judgment.

Examined the quality of group judgment in situations in which groups have to express an opinion in quantitative form. To provide a measure for evaluating the quality of group performance (which is defined as the absolute value of the discrepancy between the judgment and the true value), 4 baseline models are considered. These models provide a standard for evaluating how well groups perform. The 4 models are: (a) randomly picking a single individual; (b) weighting the judgments of the individual group members equally (the group mean); (c) weighting the 'best' group member (i.e., the one closest to the true value) totally where the best is known, a priori , with certainty; (d) weighting the best member totally where there is a given probability of misidentifying the best and getting the 2nd, 3rd, etc, best member. These 4 models are examined under varying conditions of group size and "bias." Bias is defined as the degree to which the expectation of the population of individual judgments does not equal the true value (i.e., there is systematic bias in individual judgments). A method is then developed to evaluate the accuracy of group judgment in terms of the 4 models. The method uses a Bayesian approach by estimating the probability that the accuracy of actual group judgment could have come from distributions generated by the 4 models. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion regulation and decision making under risk and uncertainty.

It is well established that emotion plays a key role in human social and economic decision making. The recent literature on emotion regulation (ER), however, highlights that humans typically make efforts to control emotion experiences. This leaves open the possibility that decision effects previously attributed to acute emotion may be a consequence of acute ER strategies such as cognitive reappraisal and expressive suppression. In Study 1, we manipulated ER of laboratory-induced fear and disgust, and found that the cognitive reappraisal of these negative emotions promotes risky decisions (reduces risk aversion) in the Balloon Analogue Risk Task and is associated with increased performance in the prehunch/hunch period of the Iowa Gambling Task. In Study 2, we found that naturally occurring negative emotions also increase risk aversion in Balloon Analogue Risk Task, but the incidental use of cognitive reappraisal of emotions impedes this effect. We offer evidence that the increased effectiveness of cognitive reappraisal in reducing the experience of emotions underlies its beneficial effects on decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Money or life: Behavioral and neural context effects on choice under uncertainty.

Despite robust evidence from behavioral decision making demonstrating context effects on choice, most neural studies on choice under risk and uncertainty have involved monetary gambles. We instructed participants to make choices under uncertainty in life and cash domains. Participants exhibited greater risk aversion, conflict, and sensitivity to negative feedback in the life domain, which we attribute to valuation of human lives. Supporting this assertion, choices to save lives activated the dorsal striatum, consistent with its role in context-sensitive reward processing. In contrast, choices to save cash activated the posterior insula, which we attribute to its role in probability signaling and risk prediction. Our findings highlight dissociable and context-dependent neural systems underlying choice under uncertainty. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

How quantity judgment changes as the number of cues increases: An analytical framework and review.

People frequently must make judgments of quantities. This article concerns how increasing the number of cues supporting such judgments affects accuracy as well as the judgment process itself. Research on these issues is sparse. This seems partly due to ambiguity about what it means to say that quantity judgments are accurate. Thus, a major focus of the article is on integrating 2 disparate approaches to analyzing quantity judgment, lens model analysis from psychology and mean squared error analysis from economic forecasting. The resulting extended mean squared error analytical scheme has general applicability. However, it offers special advantages for studying increasing information effects. The proposed scheme is used as a conceptual framework for discussing hypotheses about specific consequences of enlarged cue sets. An especially surprising conclusion is that the variability in people's judgments tends to decrease rather than increase with additional cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)