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Task bias and the accuracy of judgment: Setting a baseline for expected group performance
Author(s) -
ReaganCirincione Patricia,
Rohrbaugh John
Publication year - 1992
Publication title -
journal of behavioral decision making
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 76
eISSN - 1099-0771
pISSN - 0894-3257
DOI - 10.1002/bdm.3960050402
Subject(s) - task (project management) , ranking (information retrieval) , assertion , population , baseline (sea) , group (periodic table) , cognitive psychology , psychology , statistics , social psychology , computer science , artificial intelligence , mathematics , oceanography , chemistry , demography , management , organic chemistry , sociology , economics , programming language , geology
When a judgment task evokes unbiased estimates (i.e. the errors in individual judgments are distributed randomly around the true value), mathematical aggregation of individual estimates, even by a simple arithmetic mean, often will outperform all group members. However, when a task evokes biased estimates, mathematical aggregation does not perform so well. In this study, simulated data were accumulated to specify the expected' accuracy of mathematical aggregation relative to the accuracy of observed judgment of individual group members under varying conditions of task bias. Three types of judgment tasks were employed: (1) single‐estimate, holistic tasks, (2) multiple‐estimate, ranking tasks, and (3) multi‐cue, decomposed tasks. Findings indicated across all task types that a large percentage of judgment‐making group estimates formed strictly by computing the arithmetic mean of individual estimates performed better than their most capable members when a judgment task evoked little or no bias, a result particularly pronounced for ranking tasks. When the task was more greatly bias‐evoking, a large percentage of parallel groups performed more poorly than average (or median) members, again a pattern more starkly evident for ranking tasks. These results suggest that the extent to which a judgment task evokes bias in a population of prospective group members is an important explanatory variable deserving much greater attention in the study of group performance. For example, an assertion about the efficacy of a particular group intervention based on a reliable demonstration of group performance as accurate as the most capable members may be unfounded when a task evokes no bias, since the baseline standard under such conditions should be much higher. By selecting tasks and populations that jointly produced highly biased estimates, researchers can lower the performance floor enough to detect (with reasonably small samples of groups) experimental effects should they occur.