Representing decision-makers using styles of behavior: An approach designed for group decision support systems

Supporting decision-making processes when the elements of a group are geographically dispersed and on a tight schedule is a complex task. Aiming to support decision-makers anytime and anywhere, Web-based group decision support systems have been studied. However, the limitations in the decision-makers’ interactions associated to this scenario bring new challenges. In this work, we propose a set of behavioral styles from which decision-makers’ intentions can be modelled into agents. The goal is that, besides having agents represent typical preferences of the decision-makers (towards alternatives and criteria), they can also represent their intentions. To do so, we conducted a survey with 64 participants in order to find homogeneous operating values so as to numerically define the proposed behavioral styles in four dimensions. In addition, we also propose a communication model that simulates the dialogues made by decision-makers in face-to-face meetings. We developed a prototype to simulate decision scenarios and found that agents are capable of acting according to the decision-makers’ intentions and fundamentally benefit from different possible behavioral styles, just as a face-to-face meeting benefits from the heterogeneity of its participants.     

Interruptions improve choice performance in gray jays: prolonged information processing versus minimization of costly errors

Under the assumption that selection favors minimization of costly errors, erroneous choice may be common when its fitness cost is low. According to an adaptive-choice model, this cost depends on the rate at which an animal encounters the choice: the higher this rate, the smaller the cost of choosing a less valuable option. Errors should thus be more common when interruptions to foraging are shorter. A previous experiment supported this prediction: gray jays, Perisoreus canadensis, were more error prone when subjected to shorter delays to access to food rewards. This pattern, though, is also predicted by an attentional-constraints model. Because the subjects were able to inspect the rewards during delays, their improved performance when subjected to longer delays could have been a byproduct of the experimentally prolonged opportunity for information processing. To evaluate this possibility, a follow-up experiment manipulated both delay to access and whether rewards could be inspected during delays. Depriving jays of the opportunity to inspect rewards (using opaque lids) induced only a small, nonsignificant increase in error rate. This effect was independent of length of delay and so the jays' improved performance when subjected to longer delays was not simply a byproduct of prolonged information processing. More definitively, even when the jays were prevented from inspecting rewards during delays, their performance improved when subjected to longer delays. The findings are thus consistent with the adaptive-choice model. Electronic Publication     

Post-decision consolidation: group members in different social settings compared to individual decision makers

Two experiments were conducted to examine how making decisions in a 3-member group affects the degree of post-decision consolidation, defined as attractiveness changes in favor of the chosen alternative. Both experiments were conducted in two sessions one week apart. In the first session (decision phase), participants estimated the importance of each of four different attributes describing two decision alternatives. They were then shown predetermined attractiveness ratings on each of the attributes and were to decide on the two alternatives, either individually or as a group. In the second session (post-decision phase), the participants were to attempt to recall the attractiveness ratings for the attributes as presented to them in session one. In both experiments, significant post-decision consolidation was found for individual decision makers but not for group members. In experiment 2, this result was replicated, no difference in consolidation being found between group members with face-to-face interaction and without.     

Individual postdecision processes in group settings

In two experiments Differentiation and Consolidation Theory (Diff Con) (Svenson, 1992) was used to investigate individual postdecision making processes in three-member groups. It was predicted that in groups in which the subjects preferred different alternatives (conflict groups), subjects would consolidate their own preferred alternative, and not the group's final decision. A second hypothesis was that no consolidation would be indicated in groups in which all members preferred the same alternative (non-conflict groups). The results showed that in conflict groups, the members who gave up their preferred alternative (minority members) consolidated their own preference, thereby significantly regretting the group decision. In contrast, members who got their own will through in the majority decision (majority members) showed no consolidation of the group decision. The corresponding pattern of results was replicated in a second experiment, using a different decision situation. The results indicated that perceptions of social support, agreement in a group and decreasing responsibility for a group's decision, could all partly substitute consolidation by attractiveness restructuring.     

Postdecision consolidation in a trend prediction task

To be able to learn from experience it is necessary to correctly apprehend experienced feedback and the situation in which it is provided. The results indicate how post-decision consolidation in complex domains may affect learning. The problem may be particularly pertinent in recurrent decision making where considerable risk is involved. The study explores the changes in aspect (signal) importance from pre- to postdiction as a function of outcome information. By postdiction we mean the remembering of an earlier prediction (cf. Hawkins & Hastie, 1990). Subjects were asked to decide on which of four alternative future price developments would follow a historical price trajectory for different commodities, and to rate the importance of each of the chosen alternative's corresponding aspects. The subjects revealed a bias in their support ratings of aspects--seeing support in aspects that traditionally (by themselves and in many contexts) would be seen as neutral or even counter-indicative of the alternative chosen. After an intermission, the subjects were also given information about what was indicated to be the actual development of the market. One group was told that their decisions were correct (irrespective of what the decisions were), another group that they were incorrect but close, a third group that they were incorrect by far, while a fourth group served as a control. Following this information the subjects were again asked to judge the importance of the aspects for their own prior decision on the most likely future development. The results indicated that outcome feed-back had an effect on post decision restructuring of facts. Subjects in the correct condition showed an average consolidation that increased the support, while the wrong conditions lead to negative consolidation (in retrospect indicating that they never found as much support for their decision in the past as they actually did). Thus, in a choice between consolidating their own initial prediction and the price trajectory they would have to live with, the decision makers consolidated the outcome. Therefore, the results of the study were related to the hindsight bias phenomenon (Fischhoff, 1975) and to Kahneman and Miller's (1986) mutability concept.     

Diagnosing agoraphobia in the context of panic disorder: examining the effect of DSM-IV criteria on diagnostic decision-making

A diagnostic and statistical manual (DSM)-IV diagnosis of agoraphobia in the context of panic disorder (PD) is based on three nosologically sufficient criteria: (1) avoidance, (2) use of companions, and (3) endurance of situations despite distress. Therefore, an agoraphobia diagnosis can be made across an extremely broad range of cases including when there are no avoidance behaviors (e.g., the patient endures the situation). It was hypothesized that clinicians do not weight these criteria equally and that the DSMs individual, sufficient criteria lead to poor inter-rater reliability. Clinicians (N=48) rated hypothetical patients with symptom profiles emphasizing each of these three criteria. Consistent with expectation, clinicians differentially weighted these criteria. Avoidance was relatively more apt to produce a diagnosis when only one criterion was emphasized in clinical vignettes. Inter-rater reliability was poor in instances when only one sufficient criterion was highlighted. Knowledge concerning DSM criteria resulted in a greater rate of agoraphobia endorsement, but knowledge did not account for the overall pattern of findings.     

Prefrontal brain activity predicts temporally extended decision-making behavior

Although functional neuroimaging studies of human decision-making processes are increasingly common, most of the research in this area has relied on passive tasks that generate little individual variability. Relatively little attention has been paid to the ability of brain activity to predict overt behavior. Using functional magnetic resonance imaging (fMRI), we investigated the neural mechanisms underlying behavior during a dynamic decision task that required subjects to select smaller, short-term monetary payoffs in order to receive larger, long-term gains. The number of trials over which the longterm gains accrued was manipulated experimentally (2 versus 12). Event-related neural activity in right lateral prefrontal cortex, a region associated with high-level cognitive processing, selectively predicted choice behavior in both conditions, whereas insular cortex responded to fluctuations in amount of reward but did not predict choice behavior. These results demonstrate the utility of a functional neuroimaging approach in behavioral psychology, showing that (a) highly circumscribed brain regions are capable of predicting complex choice behavior, and (b) fMRI has the ability to dissociate the contributions of different neural mechanisms to particular behavioral tasks.     

Semantic gender assignment regularities in German

Gender assignment relates to a native speaker's knowledge of the structure of the gender system of his/her language, allowing the speaker to select the appropriate gender for each noun. Whereas categorical assignment rules and exceptional gender assignment are well investigated, assignment regularities, i.e., tendencies in the gender distribution identified within the vocabulary of a language, are still controversial. The present study is an empirical contribution trying to shed light on the gender assignment system native German speakers have at their disposal. Participants presented with a category (e.g., predator) and a pair of gender-marked pseudo-words (e.g., der Trelle vs. die Stisse) preferentially selected the pseudo-word preceded by the gender-marked determiner "associated" with the category (e.g., masculine). This finding suggests that semantic regularities might be part of the gender assignment system of native speakers.     

Beyond the Obvious: Chronic Vividness of Imagery and the Use of Information in Decision Making

The authors investigate two competing hypotheses about how chronic vividness of imagery interacts with the vividness and salience of information in decision making. Results from four studies, covering a variety of decision domains, indicate that chronic imagery vividness rarely amplifies the effects of vivid and salient information. Imagery vividness may, in fact, attenuate the effects of vivid and salient information. This is because, relative to nonvivid imagers, vivid imagers rely less on information that appears obvious and rely more on information that seems less obvious. This tendency is so robust that vividness of imagery may amplify the effects of vivid information only when this information is the only information available in the decision field. The findings seem to reflect vivid imagers' tendency to totally immerse themselves in a decision problem and scrutinize the available information creatively.     

循证医学的辩证思维

随着临床医学的发展,临床医生面临着从理论知识加个人经验的医学模式向以科学证据为基础的医学模式转变。越来越多的卫生政策和诊疗指南的制定需要以高质量的研究结果为依据,如随机对照研究的结果,特别是随机对照研究的系统综述结论。循证医学模式要求医生在临床工作中不断提出问题并通过严格的科研设计来回答这些问题,同时强调不断进行知识更新,掌握最新研究证据以指导其临床工作。同时政府部门也鼓励发展循证医疗,因为它可通过研究有效的诊疗手段来提高卫生保健的效率。此外还有迹象表明法律决策过程中要参考是否遵循了研究证据和临床指南。知情的服务对象也促使临床工作者寻求研究证据作为依据,为了提高服务质量并且充分把握特殊专业领域的现状,临床工作者也需要不断了解新的依据信息。在众多的研究信息中,我们应对每项证据的研究方法、研究对象及观察的终点进行认真分析,确定该结论是否真实并适合我们的实际,从而制定有据可查的诊疗方案。