The starting point for the research on computer-mediated legal argument is that a computer system can support lawyers by mediating the process in which they draft and generate arguments: the system can administer and supervise the argument process by keeping track of the reasons adduced and the conclusions drawn, and by checking whether the users of the system obey the pertaining rules of argument, e.g., those related to the division of burden of proof.
Computer-mediated legal argument poses a new problem: how should an argument be presented to the users of the mediating system? Especially with regards to recently developed logical tools (e.g., Hage, Prakken, Sartor, Verheij), there is little experience with argument presentation. There is a natural division of approaches to argument presentation in two classes: the verbal and the visual approaches. In the verbal approach, the argument is mainly presented in a verbal style, for instance in the form of a text or a written-out dialog. In the visual approach, the argument is mainly presented in a visual style, for instance in the form of a tree of sentences.
In the paper, we reconstruct elements of a Dutch Supreme Court case on tort law (March 20, 1992) and its sequel at the Court of Justice of The Hague (September 15, 1994) in two prototypical systems for the mediation of legal argument. The first system takes the verbal approach; the second system takes the visual approach.
We discuss the opportunities of the two approaches for presenting legal argument. Our conclusion is that neither approach is fully satisfactory if it is taken to its extreme, but that a hybrid combination of verbal and visual elements should be striven for.
Verheij, B., and Lodder, A.R. (1998). Computer-mediated legal argument: the verbal vs. the visual approach. Proceedings of the 2nd French-American Conference on Artificial Intelligence and Law - June 11-12. Nice, France.