Collaborative planning and prediction: Does group discussion affect optimistic biases in time estimation?

Abstract Intuition and previous research indicate that individuals commonly display an optimistic bias in time prediction. The present studies extend research on task completion forecasts to examine tasks performed collaboratively by groups, and predictions generated through group discussion. Participants predicted—individually and collaboratively—when they would complete upcoming group projects ranging from brief laboratory tasks to extensive real-world projects, and their actual completion times were measured. Results supported the three guiding hypotheses. First, there was an optimistic bias for both individual (Studies 1 and 2) and group predictions (Studies 1–3). Second, predictions generated through group discussion were more optimistic than those generated individually. Third, this “group accentuation” effect was mediated by the informational focus at the time of prediction. Group discussion heightened participants’ tendency to focus primarily on factors promoting successful task completion, and this selective focus on “planning for success” enhanced their optimistic outlook. Discussion centers on theoretical contributions to the individual and group decision making literatures, as well as applied implications for planning and forecasting within organizational contexts.

[1]  Verlin B. Hinsz,et al.  The emerging conceptualization of groups as information processors. , 1997, Psychological bulletin.

[2]  R. Buehler,et al.  The Role of Motivated Reasoning in Optimistic Time Predictions , 1997 .

[3]  R. Hastie,et al.  Proper analysis of the accuracy of group judgments , 1997 .

[4]  Jeffrey T. Polzer,et al.  Positive Illusions about Oneself and One's Group , 1997 .

[5]  Nancy Paule Melone,et al.  The base-rate fallacy : contrasting processes and outcomes of group and individual judgment , 1990 .

[6]  P. Hall,et al.  Great Planning Disasters , 2019 .

[7]  E. Weldon,et al.  Processes that mediate the relationship between a group goal and improved group performance. , 1991, Journal of personality and social psychology.

[8]  Robert J. Genetski,et al.  Long-Range Forecasting: From Crystal Ball to Computer , 1981 .

[9]  I. Steiner.  Group process and productivity , 1972 .

[10]  H. Gerard,et al.  Emotional uncertainty and social comparison. , 1963, Journal of abnormal and social psychology.

[11]  R. Buehler,et al.  Frequency, Probability, and Prediction: Easy Solutions to Cognitive Illusions? , 1999, Cognitive Psychology.

[12]  Linda Argote,et al.  Individual versus group use of base-rate and individuating information , 1986 .

[13]  A. Vinokur,et al.  Effects of partially shared persuasive arguments on group-induced shifts: A group-problem-solving approach. , 1974 .

[14]  R. Scott Tindale,et al.  Decision errors made by individuals and groups. , 1993 .

[15]  Shelley E. Taylor,et al.  Harnessing the imagination. Mental simulation, self-regulation, and coping. , 1998, The American psychologist.

[16]  Rebecca A. Henry,et al.  Improving Group Judgment Accuracy: Information Sharing and Determining the Best Member , 1995 .

[17]  J. H. Davis,et al.  Group decision making and quantitative judgments: A consensus model. , 1996 .

[18]  S. Byram,et al.  Cognitive and motivational factors influencing time prediction. , 1997 .

[19]  R. Buehler,et al.  Exploring the "planning fallacy": Why people underestimate their task completion times. , 1994 .

[20]  Janet A. Sniezek,et al.  Groups under uncertainty: An examination of confidence in group decision making☆ , 1992 .

[21]  M. Ross,et al.  Assessing the Accuracy of Predictions about Dating Relationships: How and Why Do Lovers’ Predictions Differ from those Made by Observers? , 1999 .

[22]  S. Plous,et al.  A comparison of strategies for reducing interval overconfidence in group judgments , 1995 .

[23]  L. K. Edwards,et al.  Applied analysis of variance in behavioral science , 1993 .

[24]  D. Kahneman,et al.  Timid choices and bold forecasts: a cognitive perspective on risk taking , 1993 .

[25]  L. Weingart.  Impact of group goals, task component complexity, effort, and planning on group performance , 1992 .

[26]  N. Kerr,et al.  Group performance and decision making. , 2004, Annual review of psychology.

[27]  U. Staudinger,et al.  Interactive minds : life-span perspectives on the social foundation of cognition , 1996 .

[28]  D. A. Kenny,et al.  Data analysis in social psychology. , 1998 .

[29]  Richard Gonzalez,et al.  Interaction with Others Increases Decision Confidence but Not Decision Quality: Evidence against Information Collection Views of Interactive Decision Making , 1995 .

[30]  Derek J. Koehler,et al.  People focus on optimistic scenarios and disregard pessimistic scenarios while predicting task completion times. , 2000, Journal of experimental psychology. Applied.

[31]  S. Lichtenstein,et al.  Do those who know more also know more about how much they know?*1 , 1977 .

[32]  Justin Kruger,et al.  If you don't want to be late, enumerate: Unpacking reduces the planning fallacy , 2004 .

[33]  Terry Connolly,et al.  Decomposed versus holistic estimates of effort required for software writing tasks , 1997 .

[34]  Søren L. Buhl,et al.  Underestimating Costs in Public Works Projects: Error or Lie? , 2002, 1303.6604.

[35]  R. Buehler,et al.  Identity Through Time , 2007 .

[36]  S. Fiske,et al.  The Handbook of Social Psychology , 1935 .

[37]  N. Epley,et al.  Feeling "holier than thou": are self-serving assessments produced by errors in self- or social prediction? , 2000, Journal of personality and social psychology.

[38]  E. F. Wright,et al.  Does group discussion facilitate the use of consensus information in making causal attributions , 1990 .

[39]  R. Buehler,et al.  Planning, personality, and prediction: The role of future focus in optimistic time predictions☆ , 2003 .

[40]  A. Tversky,et al.  Intuitive Prediction: Biases and Corrective Procedures , 1982 .

[41]  N. Kerr,et al.  Bias in judgment: Comparing individuals and groups. , 1996 .

[42]  J. S. Shrauger,et al.  Accuracy of Self-Predictions Versus Judgments by Knowledgeable Others , 1996 .

[43]  Caroline A. Bartel,et al.  Talking about time: Effects of temporal planning and time awareness norms on group coordination and performance. , 2003 .

[44]  Janet A. Sniezek,et al.  Revision, Weighting, and commitment in consensus group judgment , 1990 .

[45]  Erica I. Desrosiers,et al.  Examining the Impact of Interpersonal Cohesiveness on Group Accuracy Interventions: The Importance of Matching versus Buffering , 2002 .

[46]  Meetings make evidence? An experimental study of collaborative and individual recall of a simulated police interrogation , 1986 .

[47]  E. A. Haggard,et al.  Intraclass Correlation and the Analysis of Variance , 1958 .

[48]  Kaoru Ono,et al.  Individual judgment and group interaction: A variable perspective approach , 1988 .

[49]  Robert L. Winkler,et al.  Aggregating Point Estimates: A Flexible Modeling Approach , 1993 .

[50]  D. Myers,et al.  The group polarization phenomenon. , 1976 .

[51]  A. Tversky,et al.  On the psychology of prediction , 1973 .

[52]  M. Ross,et al.  The motivational impact of temporal focus: thinking about the future and the past. , 1996, Annual review of psychology.

[53]  Janet A. Sniezek,et al.  Situational factors affecting judgments of future performance , 1993 .

[54]  Stephen W. Raudenbush,et al.  Hierarchical linear models and experimental design. , 1993 .

[55]  Hinsz.  Group Decision Making with Responses of a Quantitative Nature: The Theory of Social Decision Schemes for Quantities. , 1999, Organizational behavior and human decision processes.

[56]  J. Scott Armstrong,et al.  Long-Range Forecasting: From Crystal Ball to Computer , 1981 .

[57]  P. Reagan-Cirincione,et al.  Improving the Accuracy of Group Judgment: A Process Intervention Combining Group Facilitation, Social Judgment Analysis, and Information Technology , 1994 .

[58]  G. Wells,et al.  Does group discussion attenuate the dispositional bias , 1985 .