Modelling Legal Argument: Reasoning with Cases and Hypotheticals, a Thesis Proposal

摘要

This thesis proposal outlines a program, HYPO, to model reasoning with cases and hypotheticals. The program comprises a means of representing and indexing cases in a Case Knowledge Base (CKB), a computational definition of relevance in terms of dimensions which capture the utility of a case for making a particular kind of argument, a dimension-based method for other cases, for making and responding to points in an argument, for asking pertinent questions and for generating hypotheticals based on seed cases in order to help an arguer formulate an argument, gather relevant facts, and explain his argument. HYPO's domain is legal argument where, as illustrated below with examples of oral arguments before the Supreme Court, experts use cases and hypotheticals as primary tools for making arguments. A real case is a case that has been litigated and decided; a hypo has not (even though it may be a very slight variation of one that has or may have been engineered to present some interesting issue not yet faced in a real case. HYPO is embedded in a larger program called COUNSELOR which emphasizes natural language understanding, generation and discourse, in the domain of strategic resource allocation.