DiaLaw: Levels, Dialog Trees, Convincing Arguments

DiaLaw is a dialogical model of legal justification. An important characteristic of the formal and implemented model DiaLaw is that both logic-based arguments and mere convincing statements can be modelled. The support of both structural (logic-based) arguments and procedural arguments (mere convincing statements) is expressed by different levels in the dialog. In this paper so-called dialog trees are used to show the connection between the assertions (both structural and procedural arguments) put forward on the different levels in the dialog. Furthermore, a definition of the previously informally introduced procedural argument is given, and procedural arguments are compared with similar features in games like MacKenzie’s DC and Bench-Capon’s TDG. Finally, it is indicated that procedural arguments cannot be defined in the logical layer, but have to be defined in the procedural layer (cf. Prakken’s layered models of argumentation).