Theory and Methods


, Volume 74, Issue 3, pp 531-553

First online:

Why Are Experts Correlated? Decomposing Correlations Between Judges

  • Stephen B. BroomellAffiliated withDepartment of Psychology, University of Illinois Email author 
  • , David V. BudescuAffiliated withDepartment of Psychology, University of IllinoisDepartment of Psychology, Fordham University

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We derive an analytic model of the inter-judge correlation as a function of five underlying parameters. Inter-cue correlation and the number of cues capture our assumptions about the environment, while differentiations between cues, the weights attached to the cues, and (un)reliability describe assumptions about the judges. We study the relative importance of, and interrelations between these five factors with respect to inter-judge correlation. Results highlight the centrality of the inter-cue correlation. We test the model’s predictions with empirical data and illustrate its relevance. For example, we show that, typically, additional judges increase efficacy at a greater rate than additional cues.


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