Chapter 1 portrayed appeal to witness testimony as a distinctive argumentation scheme with a matching set of critical questions. This approach implies that any given instance of an appeal to witness testimony in a trial needs to be evaluated in the context of a dialogue, in line with the goal appropriate for that type of dialogue. Chapter 4 outlined several different abstract models of dialogue that have been identified in the literature on argumentation theory and computing. Chapter 5 outlined the characteristics of one particular type of dialogue called peirastic examination dialogue that is new on the scene and has been very little investigated in the literature. The most visible and best established instance of this type of dialogue is found in the examination procedure used in our legal system to question witnesses and other participants in a trial. In Sections 6 and 7 of Chapter 5, the abstract model of peirastic examination dialogue was illustrated by features of examination in a trial setting. Now a large question is raised: How can we apply these abstract dialectical models to the existing institution called the trial in law?

What sort of dialogue provides the right framework for making witness testimony a form of evidence in a trial? In this chapter we will concentrate on the adversarial theory, embodied in Anglo-American law, where the opposed advocacy arguments of both sides offer the trier a basis for judging which side has the stronger argument, or a strong enough argument to meet the requirements of proof.