Human Information Processing and Adjudication: Trial by Heuristics

Abstract

This article addresses the role of quantitative evidence and methods in trials. Major arguments against the introduction of explicit computation information are considered and contrasted with findings about the characteristics of the unaided human decision maker. Emphasis is given to behavioral decision theory and the heuristic biases it reveals. Consideration is given to the symbolic versus “truth-finding” functions of trials, mathematical models (especially linear) of decision making, advocacy tactics that follow from what has been learned about how humans process information, the diagnostic value of aggregate probabilities, the notion of particularistic proof, and the evaluation of witness credibility. We conclude that unaided human decision making embodies certain normal and lawful errors, and that the exclusion of mathematical guides to aid a fact finder, while avoiding some problems, exposes the fact-finding process to the heuristic biases of intuitive decision making.