Factors affecting decision makers' preference for unshared information.

Two experiments examined solicitation of information in a group structured as a judge–advisor system (JAS) with 1 group member designated as the decision maker and the other 2 members as advisors. The decision maker solicited information from 2 advisors. One advisor's information was shared in common with the decision maker, and the other's information was predominantly unshared. In 2 experiments, decision makers asked for more information from the advisor with unshared information and rated this advisor's information as more important and influential than the advisor with only redundant, shared information. When decision makers were not limited in the amount of information they could ask for, decision makers significantly increased requests for information from the advisor with shared information but not the advisor with unshared information. Experiment 2 found that whether or not an advisor agreed with the decision maker did not affect decision makers' preference for the advisor with unshared information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

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. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

It's Good to Be Leader: The Influence of Randomly and Systematically Selected Leaders on Decision-Making Groups.

Research on hidden profiles reveals that groups often have trouble utilizing unshared information and making the optimal decision in decision-making contexts. However, a directive group leader advocating the best decision can help a group overcome this problem. The current study examines how a leader's access to information affects the quality of group decisions and information sharing. In addition, how leader selection processes affect leader influence is considered. Overall, evidence is found indicating a leader's access to information and leader selection processes influence group discussions and decision quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discussion of shared and unshared information in decision-making groups.

Investigated the effects of task importance and group decision training on the discussion behavior of decision-making groups. 73 3-person groups decided which of 3 hypothetical faculty candidates would be the best person to teach an introductory psychology course. Prior to discussion, some of the information about each candidate was given to all group members (shared information), whereas the remainder was randomly divided among them (unshared information). Groups discussed much more of their shared information than their unshared information. Increasing the importance of the task slowed the rate at which information was brought forth during discussion. By contrast, group decision training increased the amount of both shared and unshared information discussed and altered the sequential flow of shared and unshared information into the discussion. Discussion in untrained groups focused first on shared information and then on unshared information; discussion in trained groups did not shift focus over time. (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)     

Diagnosing groups: The pooling, management, and impact of shared and unshared case information in team-based medical decision making.

The impact of group discussion on the decision-making effectiveness of medical teams was examined. Three-person teams of physicians diagnosed 2 hypothetical medical cases. Some of the information about each case was given to all team members prior to discussion (shared information), whereas the rest was divided among them (unshared information). Compared with unshared information, shared information was more likely to be pooled during discussion and was pooled earlier. In addition, team leaders were consistently more likely than other members to ask questions and to repeat shared information and, over time, also became more likely than others to repeat unshared information. Finally, pooling unshared (but not shared) information improved the overall accuracy of the team diagnoses, whereas repeating both shared and unshared information affected bias (but not accuracy) in the diagnoses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group recall: The picture-superiority effect with shared and unshared information.

Previous research has examined how group characteristics can affect the pooling of unshared information (G. M. Wittenbaum & G. Stasser, 1996), but it has not explored the effect of the information itself. The present study investigated how representation of information (i.e., pictures vs. words) can affect the recall of shared and unshared information. Participants studied shared pictures, shared words, unshared pictures, and unshared words and then did 2 group recalls. On Trial 1, groups recalled more shared than unshared information and more pictures than words. On Trial 2, groups recalled more unshared pictures than unshared words, but no difference was found between the recall of shared pictures and shared words. Information salience and group coordination are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Team reflexivity, development of shared task representations, and the use of distributed information in group decision making.

Decision-making groups often exchange and integrate distributed information to a lesser extent than is desirable for high-quality decisions. One important reason for this lies in group members’ understanding of the decision task—their task representations—specifically the extent to which they understand the importance of exchange and integration of information. The authors hypothesized that a group’s development of a (shared) understanding of the information elaboration requirements of their task is influenced by collective reflection on the task. When not all group members initially realize the importance of information elaboration, team reflexivity increases the degree to which the group understands the importance of information elaboration. In an experiment, the authors showed that team reflection fostered the development of task representations emphasizing information elaboration and subsequent information elaboration and decision quality. When all members initially already held representations emphasizing information elaboration, team reflection promoted elaboration and performance to a lesser degree. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnosing groups: Charting the flow of information in medical decision-making teams.

Several hypotheses derived from an information sampling model of group discussion were tested with 3-person teams of physicians given 2 hypothetical medical cases to diagnose. Some of the information about each case was given to all 3 team members before discussion (shared information), whereas the rest was divided among them (unshared information). As predicted, shared information was, overall, more likely to be discussed than unshared information, and it was brought into discussion earlier. In addition, it was found that team leaders repeated substantially more case information than did other members and that, over time, they repeated unshared information at a steadily increasing rate. The latter findings are interpreted as evidence of leaders' information management role in problem-solving discussions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2011 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)     

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)     

The evolution of hexamerins and the phylogeny of insects

The impact of group discussion on the decision-making effectiveness of medical teams was examined. Three-person teams of physicians diagnosed 2 hypothetical medical cases. Some of the information about each case was given to all team members prior to discussion (shared information), whereas the rest was divided among them (unshared information). Compared with unshared information, shared information was more likely to be pooled during discussion and was pooled earlier. In addition, team leaders were consistently more likely than other members to ask questions and to repeat shared information and, over time, also became more likely than others to repeat unshared information. Finally, pooling unshared (but not shared) information improved the overall accuracy of the team diagnoses, whereas repeating both shared and unshared information affected bias (but not accuracy) in the diagnoses.     

Accountability and the discussion of unshared, critical information in decision-making groups.

Previous research has demonstrated that groups are more likely to discuss information shared by all group members than unshared information (G. M. Wittenbaum & G. Stasser, 1996). In the present study, it was hypothesized that groups may be less likely to overlook unshared information when they are held accountable to an audience outside the group for their decisions. University students read a murder mystery and then met in 3-person groups to select who they thought was most likely to have committed the crime. Contrary to hypotheses, the results showed that accountable groups were less likely to focus on unshared information than groups who were not held accountable because of an increased focus on irrelevant details by accountable groups. Implications for future research are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does the Stepladder Technique improve group decision making? A series of failed replications.

Past research has demonstrated the effectiveness of a structured group decision-making technique, termed the Stepladder Technique, in improving group decisions. The purpose of the present series of studies was to replicate and extend this research. Five studies (three using different tasks than previous studies and two using the same task) compared the decision quality of groups using the self-paced Stepladder Technique to unstructured groups. In all studies, stepladder groups failed to perform better than unstructured groups. This failure to replicate and extend past research suggests that there are definite boundaries, such as the sample or the experimenter, which may limit the overall effectiveness of the Stepladder Technique. (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)     

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)