Group decision making in hidden profile situations: dissent as a facilitator for decision quality

The effect of diversity in individual prediscussion preferences on group decision quality was examined in an experiment in which 135 three-person groups worked on a personnel selection case with 4 alternatives. The information distribution among group members constituted a hidden profile (i.e., the correct solution was not identifiable on the basis of the members' individual information and could be detected only by pooling and integrating the members' unique information). Whereas groups with homogeneous suboptimal prediscussion preferences (no dissent) hardly ever solved the hidden profile, solution rates were significantly higher in groups with prediscussion dissent, even if none of these individual prediscussion preferences were correct. If dissent came from a proponent of the correct solution, solution rates were even higher than in dissent groups without such a proponent. The magnitude of dissent (i.e., minority dissent or full diversity of individual preferences) did not affect decision quality. The beneficial effect of dissent on group decision quality was mediated primarily by greater discussion intensity and to some extent also by less discussion bias in dissent groups.     

多决策方法多交流方式的群体决策比较

采用人员选拔的实验室模拟实验,以160名被试组成40个4人群体,对4种决策方法和2类交流方式的群体决策进行了比较。结果发现（1）决策方法和交流方式对于讨论过程的信息交流具有显著影响;（2）以计算机为中介进行决策的被试知觉到的任务难度要高于面对面决策条件;决策方法对于群体成员有关实验任务难度知觉具有主效应;交流方式和决策方法对于群体决策过程满意感和结果满意感没有显著影响;（3）在以投票轮次来表明群体达成一致意见所需时间上,决策方法对于投票轮次具有显著影响。恶魔式辩护、辨证式查询两种方法下所需的投票轮次多于专家意见法和自由讨论法的投票轮次。     

面对面和计算机群体决策运用排序法上的比较

通过人员选拔的实验室模拟实验．比较面对面的和以计算机为中介的决策群体在信息是否完全分享及是否采用排序法决策条件下对于决策效标的影响。结果表明：(1)决策前的信息分享通过决策前偏好的人数构成影响了最终的决策准确率。(2)排序法在面对面交流时只在信息非分享的情况下才显著增加了关键信息交流;排序法在计算机交流和信息完全分享下显著增加了关键信息交流。弥补了Hollingshead的研究不足之处。排序法不损害成员对于讨论的满意感。(3)计算机交流更关注文本信息,有更多争论、自我观点阐述和申诉。在关键信息交流上与面对面交流没有差异。(4)在决策准确性上,不同的交流方式没有差异。     

Microlevel Structuration in Computer-Supported Group Decision Making

The theory of Structuration focuses on how actions by members of social collectives create the structures that enable and constrain future action. Most previous research on Structuration in groups and organizations used qualitative case studies because Structuration is quite complex. This study introduces a method for the study of Structuration in larger samples of groups or organizations. A category system for the identification of structuring moves is described, along with several methods for characterizing short- and long-term trends in Structuration processes. The method is used to study how groups incorporate a computerized group decision support system (GDSS) into their decision processes. GDSSs are part of a class of new computer and communication technologies designed to help groups improve their meetings and make better decisions. Because GDSSs must be used by a group rather than an individual, social processes are critical in determining their effects on group outcomes. GDSSs influence groups by structuring their activities, and structurational processes are critical mediators of the impacts of GDSSs on group decision making. The study focused on the effects of restrictiveness of GDSS technology on Structuration processes and, in turn, on the relation of Structuration to a key group outcome, consensus change. The results suggest that two major types of structuring processes occur in computer-supported groups and that the nature of structuration is related to degree of consensus change.     

Decision Development in Computer-Assisted Group Decision Making

New computer technologies to aid group communication and decision making are becoming increasingly widespread. This study analyzes how one such technology, a group decision support system (GDSS), affected how group decisions developed over time. The study contrasted decision paths in groups using the GDSS with groups using the same procedural structures incorporated in the GDSS manually and with groups using no procedural structures. A flexible phase mapping method was employed to map group decision paths. The resulting set of seven decision paths varied in both sequence and number of decision phases. An optimal matching procedure was used to compute similarity measures among the 40 paths, and cluster analysis and multidimensional scaling were used to generate an empirical taxonomy of decision paths. Results indicated that the nature of decision paths varied both across the three conditions and within conditions. The decision path types were also related to three outcome variables: consensus change, perceived decision quality, and decision scheme satisfaction. Results indicated that those decision paths that most resembled logical normative sequences had superior outcomes to those that did not.     

Information sampling and group decision making: the effects of an advocacy decision procedure and task experience

Group discussions tend to focus on information that was previously known by all members (shared information) rather than information known by only 1 member (unshared information). If the shared information implies a suboptimal alternative, this sampling bias is associated with inaccurate group decisions. The present study examines the impact of 2 factors on information exchange and decision quality: (a) an advocacy group decision procedure versus unstructured discussion and (b) task experience. Results show that advocacy groups discussed both more shared and unshared information than free-discussion groups. Further, with increasing experience, more unshared information was mentioned in advocacy groups. In contrast, there was no such increase in unstructured discussions. Yet advocacy groups did not significantly improve their decision quality with experience.     

Biased information search in group decision making

Research has shown that people prefer supporting to conflicting information when making decisions. Whether this biased information search also occurs in group decision making was examined in three experiments. Experiment 1 indicated that groups as well as individuals prefer supporting information and that the strength of this bias depends on the distribution of the group members' initial decision preferences. The more group members had chosen the same alternative prior to the group discussion (group homogeneity), the more strongly the group preferred information supporting that alternative. Experiment 2 replicated these results with managers. Experiment 3 showed that the differences between homogeneous and heterogeneous groups reflect group-level processes. Higher commitment and confidence in homogeneous groups mediated this effect. Functional and dysfunctional aspects of biased information seeking in group decision making are discussed.     

群体决策过程中的信息取样偏差

一般认为,决策群体的优势是能综合各个成员拥有的不完整信息,形成对所有决策备择方案的无偏差的认识,从而作出最佳选择。但“群体讨论中的有偏差信息取样模型’认为,群体在决策中往往表现出倾向于讨论两种信息：(1)各成员讨论前都拥有的信息;(2)支持成员在讨论前所偏好的信息。该实验通过模拟人员选拔决策形式的实验室实验,对这一模型的假设进行验证。研究结果表明,大多数群体选择了一开始受到大多数成员支持的候选人,而非实际的最佳人选;群体讨论非但未纠正,反而加强了成员对候选人原有的歪曲印象。     

Biased information search in homogeneous groups: confidence as a moderator for the effect of anticipated task requirements

When searching for information, groups that are homogeneous regarding their members' prediscussion decision preferences show a strong bias for information that supports rather than conflicts with the prevailing opinion (confirmation bias). The present research examined whether homogeneous groups blindly search for information confirming their beliefs irrespective of the anticipated task or whether they are sensitive to the usefulness of new information for this forthcoming task. Results of three experiments show that task sensitivity depends on the groups' confidence in the correctness of their decision: Moderately confident groups displayed a strong confirmation bias when they anticipated having to give reasons for their decision but showed a balanced information search or even a dis confirmation bias (i.e., predominately seeking conflicting information) when they anticipated having to refute counterarguments. In contrast, highly confident groups demonstrated a strong confirmation bias independent of the anticipated task requirements.     

Test of a Level of Aspiration model of group decision making: Non-obvious group preference reversal due to an irrelevant alternative

We conducted two experiments that investigated a non-obvious prediction of a Level of Aspiration (LOA) model of group decision making. In both experiments, groups chose among three alternatives, A, B, and C, with C always being least preferred by all of the group members. In each experiment, by manipulating the nature of alternative C, we created two conditions differing in whether only A or only B was acceptable to all members. In support of the LOA model, groups tended to choose the alternative acceptable to all members, even when (Experiment 2) a majority of members most preferred a different alternative. Implications of the results for the LOA model are discussed in the context of social choice theory.     

不同沟通方式下群体决策信息利用分析

以180名被试组成45个四人群体．完成模拟人事选拔的问题解决型任务,通过对群体决策过程的信息提取数量和提取次序的分析,考察不同的沟通方式和信息分享程度对群体决策信息利用的影响。结果表明。（1）在不同沟通方式下,决策成员的讨论前偏好对最终决策的影响很大。（2）在不同的沟通方式下,分享程度不同的信息在决策过程中的提取具有差异,体现了不同的规律。     

团体决策支持系统和团体讨论对团体决策的影响

通过模拟实验的方法,探讨了团体决策支持系统（GDSS）和团体讨论对团体决策的影响。以大学生为被试,运用小组决策任务,对小组决策过程进行了研究。实验记录了在有无GDSS的支持和有无团体讨论两个变量所决定的4种实验条件下,小组决策取得结果的正确性和组内的一致性。用ANOVA方法分析了4种条件下的实验结果,发现GDSS能提高团体决策的正确性,而团体讨论将有助于成员做出一个正确的、一致的决策     

The fundamentality of group principles and perceived group entitativity

We argue that the level of consensus about a set of social identity principles, and their perceived fundamentality, can influence the degree to which members perceive their group as an entity. This idea was explored through an experiment in which participants judged the entitativity of specific (in)groups on the basis of the distribution of the opinions held by their members about three identity-related principles that participants had previously rated for fundamentality. The results demonstrated that the more fundamental a principle was judged to be in comparison to other principles, the more important consensus about that principle was for producing group entitativity, relative to consensus about other principles.     

Who’s bringing the donuts: The role of affective patterns in group decision making

Two studies examined how intragroup affective patterns influence groups’ pervasive tendency to ignore the unique expertise of their members. Using a hidden profile task, Study 1 provided evidence that groups with at least one member experiencing positive affect shared more unique information than groups composed entirely of members experiencing neutral affect. This occurred because group members experiencing positive affect were more likely to initiate unique information sharing, as well as information seeking. Study 2 built upon this base by showing that confidence mediates the relationship between positive affect and the initiation of unique information sharing. Additionally, Study 2 investigated the role of negative affect in group decision making and how negative and positive affect concurrently influence decision making when groups are composed of members experiencing each. The results are discussed in terms of the role affect plays in influencing group behavior and the resultant importance of investigating specific affective patterns.     

The Formation of Attitudes Toward New Immigrant Groups1

People often receive information about new immigrant groups prior to any direct contact with group members. However, it is not clear how this information shapes attitudes toward the groups. To explore this issue, 204 subjects were told about an unknown immigrant group that was presented as high or low in personal relevance. Subjects were then given positive or negative consensus information about the emotions that group members elicit from others, group members' personality traits, and group members' values. As expected, results indicated that the presentation of positive information about emotional reactions, personality traits, and values caused attitudes to be more favorable than did the presentation of negative information. Importantly, however, the combined impact of the emotion and personality trait information depended on whether the group was perceived to be of high or low personal relevance. Specifically, when the information about emotions and personality traits was similarly valanced (i.e., both were positive or both were negative), attitudes toward the group tended to be less favorable in the high personal relevance condition than in the low personal relevance condition. In contrast, when mixed information was presented (i.e., positive emotions and negative personality traits or negative emotions and positive personality traits), attitudes tended to be more favorable in the high personal relevance condition. In addition, attitudes, once formed, predicted further perceptions of the group and behavioral intentions toward group members. The implications of the findings for the reduction of prejudice toward new immigrant groups are discussed.     

Polarization as a function of meaning and consequences

Studied the effect of meaning and consequences on shifts toward extreme judgments (polarization) as a result of group discussion. Since it was hypothesized that high levels of both meaning and consequences would activate pressures to conform to the appropriate cultural norm, greater polarization was predicted under those conditions. Consequences were varied by asking subjects how willing they were to participate in another actual (high consequences) or hypothetical (low consequences) experiment. Meaning was varied by information that the proposed experiment would have high or low social and scientific significance. Sixty male college students discussed their preferences in three-person groups. Prediscussion, consensus, and postdiscussion scores were obtained; the critical polarization scores were computed on the basis of individual's movement away from the prediscussion mean of their group. Partial support for the hypotheses is provided by a cross-over interaction (p < .05) in changes from the prediscussion to consensus scores, which indicate greater polarization in the high-meaning, low-consequence condition, and in the low-meaning, high-consequence condition. The results are discussed with respect to their implications for research in which subjects do not expect real consequences to follow from their statements of opinion.     

自由讨论条件下群体决策质量的影响因素

通过实验室实验考察了自由讨论条件下群体决策质量的影响因素,并对Stasser所提出的信息取样模型进行了验证,结果发现：(1)部分证实Stasser的信息取样模型。在信息不分享的条件下,如果讨论前群体成员的偏好比较一致时,群体的确倾向于讨论分享信息和群体所偏好的候选人的信息;但如果讨论前的偏好不一致或任务难度较低时,这一结论难以成立。(2)自由讨论条件下,群体规模的增加会增加分享信息的讨论量,而对非分享信息的讨论程度则无显著影响。而在任务难度方面,只有任务难度较大的情况下才有分享信息的讨论优势。     

Quality of decision making and group norms.

Two studies investigated the impact of group norms for maintaining consensus versus norms for critical thought on group decisions in a modification of the biased sampling paradigm (G. Stasser & W. Titus, 1985). Both studies showed that critical norms improved the quality of decisions, whereas consensus norms did not. This effect appeared to be mediated by the perceived value of shared and unshared information: Consensus norm groups valued shared information more highly than critical groups did, and valence was a good predictor of decision outcome. In addition, the 2nd study showed that the group norm manipulation has no impact on individual decisions, consistent with the assumption that this is a group effect. Results suggest that the content of group norms is an important factor influencing the quality of group decision-making processes and that the content of group norms may be related to the group's proneness for groupthink.     

Intra‐group interaction and the development of norms which promote inter‐group hostility

Research suggests there is more inter‐group discrimination when rewards rather than punishments are distributed between groups (the positive‐negative asymmetry effect). This study investigated whether intra‐group interaction and the obstruction of in‐group advancement moderate this finding. Participants were twice asked to divide monetary resources—individually (pre‐consensus) and in interactive groups (consensus). Results confirmed that there was more discrimination when rewards were allocated. Although this replicates the PNAE overall, there were two moderators. First, there was no asymmetry when the out‐group obstructed in‐group advancement: obstruction was sufficient to legitimise punishment. Second, after group interaction the PNAE reversed so that there was more discrimination when punishments were administered. The severity of discrimination was contingent upon group norms that endorsed inter‐group hostility. It is argued that norms changed as a function of group interaction, and so did patterns of discrimination. The results suggest that the intra‐and inter‐group context combined to cause in‐group favouritism to slide towards inter‐group hostility. Copyright © 2007 John Wiley & Sons, Ltd.     

The frequency and effect on outcome of different types of interpretation in psychodynamic and cognitive-behavioral group psychotherapy

The therapeutic effects of interpretations by both therapists and other clients were recorded by observers in three cognitive-behavioral and three psychodynamic groups over a period of thirty one-and-one-half-hour group therapy sessions. There was no significant difference in the overall frequency of interpretations made in the two different therapy modalities; however, there was the expected difference in the types of interpretations made. Cognitive-behavior therapists and group members tended to interpret patterns of behavior or impact on others more frequently than did psychodynamic therapists and group members; while psychodynamic therapists and group members made more historical cause interpretations. However, contrary to expectations, both therapy modalities made more interpretations of patterns of present behavior than any other type. When these interpretations were converted into problem statements that were sent to outside raters after the termination of the groups, the outside raters judged that clients improved most when interpretations of a pattern of behavior were made; next most when interpretations of impact on others were made; and did not improve when interpretations of motive were employed in either modality.