Representing the structure of a legal argument

The investigation described in this paper is part of a larger project to characterize and develop computational tools to help people formulate, record, and present arguments and rationale in diverse domains such as law, policy, and design where argumentation and decision-making are fundamental processes. To build such tools, it is necessary first to design a uniform representation for the structure of arguments; law has provided us with a good starting point for understanding this structure. Since arguments are important legal artifacts, law maintains a recorded institutional memory of them in forms such as casebooks, databases, and courtroom transcripts. This analysis is primarily concerned with the arguments that occur in two excerpts from Supreme Court oral argument transcripts; it is directed toward developing a system of semi-formal representations of the structure of these arguments in hypertext. A system of representations of argument structure, coupled with an understanding of the argumentation process, can be used to form the basis for tools for authoring, fault-detection, and other activities associated with formulating and presenting rationale.