Information pooling: When it impacts group decision making.

Three-person groups decided which of 2 professors was nominated for a teaching award. Prior to discussion, half of the information available for this decision was given to every group member (shared information), whereas the rest was evenly divided among them (unshared information). Further, this information was distributed in such a way that the correct choice was not obvious to members prior to discussion. As predicted, discussion focused more on members' shared than unshared information. However, decision quality was affected only by the amount of unshared information discussed and by member's prediscussion choice preferences. The amount of shared information discussed did not affect decision quality. These results suggest a dual-process model of how the prediscussion distribution of decision-relevant information impacts group decision-making effectiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowing others' preferences degrades the quality of group decisions.

Results from 4 experiments demonstrate that learning the other group members' preferences at the beginning of a discussion impedes the solution of hidden profiles. In Experiments 1–3, participants who were not informed about their fellow group members' preferences were more likely to solve a hidden profile than those who received bogus information about the others' preferences. The negative effect of learning the others' preferences on decision quality was mediated by participants paying less attention to the information exchanged when they had been made aware of the others' preferences. Experiments 1 and 2 further ruled out that the effect of learning the others' preferences is due to participants bolstering their position or due to an increase in informational load. Experiment 3 showed that learning the other group members' preferences impedes the solution of hidden profiles even if one of the other members favors the correct alternative. Finally, Experiment 4 replicated these results in face-to-face interacting 3-person groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving group decisions by better pooling information: A comparative advantage of group decision support systems.

This study compared a group decision support system (GDSS) with face-to-face (FTF) group discussion on characteristics of information exchange and decision quality. Participants given conflicting information tended to share more of their unique data and engaged in more critical argumentation when using the GDSS than when meeting FTF. Conversely, when information was consistent among members, there were no such differences between FTF and GDSS groups. The GDSS groups significantly outperformed the FTF groups in agreeing on the superior hidden profile candidate, especially when there was a lack of prediscussion consensus. Individual-level analyses revealed that members of GDSS groups that did not have a prediscussion consensus tended to experience stronger preference shifts toward the group's consensus decision. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group and computer-mediated discussion effects in risk decision making.

Managers individually and in 3-person groups made multiattribute risk choices (two investment alternatives, each with multiple outcomes). Two group decisions were reached during face-to-face discussion, and two were reached during (real-time) computer-mediated discussion. In comparison with prediscussion individual preferences, groups' multiattribute risk choices and attitudes after face-to-face discussion were risk averse for gains and risk seeking for losses, a tendency predicted by prospect theory and consistent with choice shift and other group extremitization research. By contrast, group decisions during computer-mediated discussion did not shift in the direction of prospect theory predictions. The results are consistent with persuasive-arguments theory, in that computer-mediated discussion contained less argumentation than face-to-face discussion. Social decision schemes were used to evaluate alternative assumptions about the group process. A "(prospect-theory) norm-wins" decision scheme described group choice well in the face-to-face discussion condition, but not in the computer-mediated discussion condition. Another decision scheme, first-advocate wins, which described choices well in both face-to-face and computer-mediated discussions, was explored in a discussion of the role of communication in group decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preference-consistent evaluation of information in the hidden profile paradigm: Beyond group-level explanations for the dominance of shared information in group decisions.

Common explanations for the failure of groups to solve so-called hidden profiles focus on group processes, namely insufficient discussion of unshared information and premature consensus on a suboptimal alternative. As 2 experiments show, even in the absence of such group processes, hidden profiles are hardly ever solved. In Experiment 1, participants first received individual information about a personnel selection task and then read a group discussion protocol containing full information exchange. If the individual information was misleading (hidden profile), most participants failed to detect the correct alternative. In Experiment 2, it was determined that this effect is due to preference-consistent evaluation of information that constitutes an individual-level process mediating the failure of group members to solve hidden profiles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Taking the easy way out: Preference diversity, decision strategies, and decision refusal in groups.

It has often been argued and found that preference diversity is beneficial for the quality of group decisions. However, this literature has neglected the fact that in many situations, it is also possible not to choose. Further, preference diversity can be based on attractions, aversions, or both. The authors argue that some types of preference diversity can lead to biased discussions and choice refusal (i.e., the group refuses to choose any of the available options). In a laboratory experiment, three different patterns were observed. When group members held different aversions before discussion, discussions were aversion driven and group members quickly agreed to refuse all alternatives. When each alternative had both a proponent and an adversary, discussions were longer and unbiased but still often led to refusal, which was accompanied by relatively low levels of outcome satisfaction. Only when preference diversity was based only on attractions did it lead to unbiased discussion, low prevalence of refusal, and high outcome satisfaction. Implications for group decision making are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Minority dissent and team innovation: The importance of participation in decision making.

This study integrates research on minority dissent and individual creativity, as well as team diversity and the quality of group decision making, with research on team participation in decision making. From these lines of research, it was proposed that minority dissent would predict innovation in teams but only when teams have high levels of participation in decision making. This hypothesis was tested in 2 studies, 1 involving a homogeneous sample of self-managed teams and 1 involving a heterogeneous sample of cross-functional teams. Study 1 suggested that a newly developed scale to measure minority dissent has discriminant validity. Both Study 1 and Study 2 showed more innovations under high rather than low levels of minority dissent but only when there was a high degree of participation in team decision making. It is concluded that minority dissent stimulates creativity and divergent thought, which, through participation, manifest as innovation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pooling of unshared information in group decision making: Biased information sampling during discussion.

Studied 4-member decision-making groups given information about 3 hypothetical candidates for student body president in unshared/consensus or shared or unshared/conflict conditions. 84 undergraduates participated in the unshared consensus condition, and 72 undergraduates participated in the other conditions. Results show that even though groups could have produced unbiased composites of the candidates through discussion, they decided in favor of the candidate initially preferred by a plurality rather than the most favorable candidate. Group members' pre- and postdiscussion recall of candidate attributes indicated that discussion tended to perpetuate, not to correct, members' distorted pictures of the candidates. It is suggested that unstructured discussion in the face of a consensus requirement may fail as a means of combining unique informational resources. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Signal-detection analysis of group decision making.

How effectively can groups of people make yes-or-no decisions? To answer this question, we used signal-detection theory to model the behavior of groups of human participants in a visual detection task. The detection model specifies how performance depends on the group's size, the competence of the members, the correlation among members' judgments, the constraints on member interaction, and the group's decision rule. The model also allows specification of performance efficiency, which is a measure of how closely a group's performance matches the statistically optimal group. The performance of our groups was consistent with the theoretical predictions, but efficiency decreased as group size increased. This result was attributable to a decrease in the effort that members gave to their individual tasks rather than an inefficiency in combining the information in the members' judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resolving meaning: Interpretation in diverse decision-making groups.

In this theoretical article, the authors develop a model that links diversity, as mediated by interpretative processes, to both performance and affective outcomes in newly formed diverse decision-making groups. Group diversity predicts the use of interpretive resolution strategies of information seeking or dialogue, which in turn influence the group's decision quality. The level of participation, influenced by group diversity, moderates the relationship between diversity and resolution strategy such that diverse groups whose members exhibit a greater degree of participation will engage in dialogue. Resolution strategy, diversity, and participation jointly affect the members' affective perceptions of satisfaction with the group process and desire to remain in the group. (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)     

Need for cognition and interpersonal influence: Individual differences in impact on dyadic decisions.

The role of need for cognition (NC; J. T. Cacioppo & R. E. Petty, 1982) in dyadic decisions was investigated. Consistent with the notion that individual differences in NC correspond to differences in attitude strength, the prediscussion views of people high in NC were found to be more predictive of dyadic decisions than were the prediscussion views of people low in NC. High-NC people were viewed by their discussion partners (and by themselves) as being more effective persuaders, generating more arguments to support their views (and thus counter those of their partners), and generating more valid arguments than their low-NC counterparts. The role of individual differences in understanding asymmetries in group member influence and in predicting collective decision outcomes is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group decision making and normative versus informational influence: Effects of type of issue and assigned decision rule.

Groups and individuals often shift their preferences following discussion of an issue. Explanations for such shifts typically invoke either informational or normative influence processes. The former refers to influence based on sharing of facts or persuasive arguments about the issue, and the latter refers to conformity to implicit decision norms and others' preferences. We investigated conditions under which one or the other influence mode predominates during discussion. Groups discussed and made decisions on either an intellective issue (attempting to discover the true or correct answer) or a judgmental issue (deciding on the moral, valued, or appropriate position), given either a unanimity or a majority decision rule. The largest shift in preference was found for the judgmental issue decided by unanimity rule. The least satisfaction with both the process and the outcome of discussion was found in groups that decided a judgmental issue under majority rule. Content analysis showed that, as expected, the intellective issue elicited more informational than normative influence, and the judgmental issue provoked more normative than informational influence. This pattern was stronger under unanimity rule than under majority rule. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of participatory and supervisory leadership on group creativity.

This study compares the creativity of 4-man groups under 2 conditions of leadership. The Ss were 90 freshmen and sophomore Navy ROTC midshipmen and 30 NROTC seniors who served as group leaders. In 15 of the groups, the leaders acted as chairmen who directed the group discussions and contributed to the task solution. In the other 15 groups, leaders acted in a supervisory capacity: they directed and guided group discussion and they were allowed to encourage members or to reject ideas, but the leaders were prohibited from contributing to the solution of the task. Groups having participatory leaders were generally superior in quantity of output while groups under supervisory leaders were superior in the quality of the product. Although leaders in the 2 conditions did not differ in their satisfaction with the group product, the participatory leaders were more satisfied with their own individual contribution to the task. The leadership styles did not produce differences in the members' esteem for the leader or in the members' morale and satisfaction with the task. Differences were found in the influence of the leader intelligence and ability scores on group creativity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On racial diversity and group decision making: Identifying multiple effects of racial composition on jury deliberations.

This research examines the multiple effects of racial diversity on group decision making. Participants deliberated on the trial of a Black defendant as members of racially homogeneous or heterogeneous mock juries. Half of the groups were exposed to pretrial jury selection questions about racism and half were not. Deliberation analyses supported the prediction that diverse groups would exchange a wider range of information than all-White groups. This finding was not wholly attributable to the performance of Black participants, as Whites cited more case facts, made fewer errors, and were more amenable to discussion of racism when in diverse versus all-White groups. Even before discussion, Whites in diverse groups were more lenient toward the Black defendant, demonstrating that the effects of diversity do not occur solely through information exchange. The influence of jury selection questions extended previous findings that blatant racial issues at trial increase leniency toward a Black defendant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ethnic diversity and distributed information in group decision making: The importance of information elaboration.

Ethnic diversity may impede groups' use of distributed information in decision making. This is not so much because diversity interferes with groups' ability to reach agreement, but because ethnic diversity may disrupt the elaboration (exchange and integration) of distributed information. The authors find evidence for this proposition in an experiment (N = 63 groups) in which ethnically diverse groups are shown to benefit more from instructions emphasizing information integration than ethnically homogeneous groups when dealing with distributed information, whereas neither ethnic diversity nor information integration instruction affected decision making performance in groups with fully shared information. These effects were mediated by a behavioral measure of group information elaboration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expert role assignment and information sampling during collective recall and decision making.

Previous research has found that decision-making groups do not effectively pool unshared information. This study examined how personal expertise facilitates the mentioning and validation of unshared information in collective recall and decision-making groups by increasing members' awareness of who holds what types of information. Assigned expertise increased substantially the proportion of unshared information mentioned during both collective recall and decision-making tasks. Two results supported the hypothesis that assigned expertise provides validation for the recall of unshared information. When expertise was assigned, (1) more of the unshared information mentioned during the recall task was retained on the collectively endorsed written protocol, and (2) unshared information that was mentioned in discussion was more likely to be correctly recognized by members after group interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)