ABSTRACT
In this chapter, the authors show that there is a more systematic method for building legal Bayesian network that can be practiced and learned by nonmathematicians. They also show that how the idioms approach enables us to build useful legal arguments in a consistent and repeatable way. The authors introduce a number of specially adapted idioms and present examples throughout of their use. They provide a comprehensive case example that puts together all of the idioms. The evidence idiom assumes that the various pieces of evidence are independent, and the assumption that makes it possible to compute the overall likelihood ratio for the combined evidence by simply multiplying the individual Legal Reasoning. The authors describe how their approach helps expose and avoid common probabilistic fallacies made in legal arguments, and also dispels the myth that Bayesian reasoning is incompatible with legal reasoning.
