That is the title of our latest paper on the blue bus problem, a favorite law-school hypothetical of torts and evidence professors. (We wrote up a first draft of our paper in Tarpon Springs, Florida during the summer of 2013 and made some stylistic as well as substantive revisions more recently in preparation for our paper’s forthcoming publication in volume 7 of the Washington University Jurisprudence Review.) Briefly, the main contribution of our paper is that we visualize the blue bus problem using Bayesian methods of probabilistic reasoning. By the way, although many legal scholars — most recently Edward Cheng — have applied Bayesian methods to the blue bus problem, none have taken a visual approach to the problem. Ironically, however, trial attorneys routinely rely on visual forms of evidence (e.g., pictures, objects, scale models, etc.) when presenting their cases to juries. In our blue bus paper, then, we follow the lead of trial lawyers and present a Bayesian approach to the blue bus problem in visual form using numerical frequencies instead of fractions or percentages. In addition to solving the blue bus problem, our larger aim is to reevaluate the problem of probabilistic proof and make the case for Bayesian methods in civil and criminal adjudication generally.
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