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)     

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)     

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)     

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)     

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.     

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)     

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)     

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)     

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)     

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)     

Mutual enhancement: Toward an understanding of the collective preference for shared information.

Groups tend to discuss and repeat information known by all members (shared) more than they do information known by one member (unshared). One factor that may influence this effect is the tendency for members to positively evaluate one another when mentioning shared information. Three experiments demonstrated this "mutual enhancement" effect. Experiment 1 showed that mutual enhancement was related to participants' and their partners' exchanging the same pieces of information. Experiment 2 illustrated that mutual enhancement was not related to the extent that participants liked partners or saw them as having similar opinions. Experiment 3 showed mutual enhancement in face-to-face dyads that discussed shared information. A combined analysis across the 3 experiments showed the robustness of mutual enhancement. Implications of mutual enhancement for group discussion are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discovery of hidden profiles by decision-making groups: Solving a problem versus making a judgment.

An information-sampling model proposed by G. Stasser and W. Titus (1985, 1987) and observations of discussion content (Stasser et al, 1989) suggest that face-to-face discussions often fail to disseminate unshared information. However, groups may be less prone to overlooking unshared information if they believe that their task has a demonstrably correct answer (P. R. Laughlin, 1980). University students read a murder mystery and then met in groups to discuss the case. Groups believed they had either sufficient (solve set) or insufficient (judge set) evidence to determine the guilty suspect. When critical clues were unshared before discussion, 67% of solve, but only 35% of judge, groups identified the guilty suspect. Discussion content analyses show that solve groups focused more on the critical clues. (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)     

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)     

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)     

Information sharing and team performance: A meta-analysis.

Information sharing is a central process through which team members collectively utilize their available informational resources. The authors used meta-analysis to synthesize extant research on team information sharing. Meta-analytic results from 72 independent studies (total groups = 4,795; total N = 17,279) demonstrate the importance of information sharing to team performance, cohesion, decision satisfaction, and knowledge integration. Although moderators were identified, information sharing positively predicted team performance across all levels of moderators. The information sharing–team performance relationship was moderated by the representation of information sharing (as uniqueness or openness), performance criteria, task type, and discussion structure by uniqueness (a 3-way interaction). Three factors affecting team information processing were found to enhance team information sharing: task demonstrability, discussion structure, and cooperation. Three factors representing decreasing degrees of member redundancy were found to detract from team information sharing: information distribution, informational interdependence, and member heterogeneity. (PsycINFO Database Record (c) 2010 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)     

Serial Position Effects and the Picture-Superiority Effect in the Group Recall of Unshared Information.

This research examined how serial position effects (i.e., primacy and recency effects) and the picture-superiority effect (i.e., the tendency to recall pictures better than words) can impact the recall of unshared information (i.e., information known by only 1 group member). In 2 experiments, participants studied a stimulus list of pictures and words and completed a group recall task. In both experiments, the authors found that the primacy effect and the picture-superiority effect influenced how much unshared information was recalled and when it was recalled. However, there was little impact of the recency effect on either how much unshared information was recalled or when it was recalled. The implications of these findings for future theoretical research and applications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)