The ASPIC+ framework for structured argumentation allows for the generation of arguments and attacks between them from a given knowledge base. A set of winning arguments is then derived by applying one of several abstract argumentation semantics, from which a corresponding set of acceptable conclusions is deduced.
Argumentative reasoning plays a central role in the legal domain, in particular in court proceedings. At the University of Luxembourg, researchers are working on an extension of ASPIC+ called ASPIC-END, which adds an explanatory dimension to the framework by not only allowing the arguments to explain each other but also making them compete for a most suitable explanation to a given set of facts or evidence.
The focus of the research activity is on the explanatory aspect of legal argumentation, which is often overlooked. For a hypothesis to be convincing, it must not only be defended from counter-arguments, but it should also be powerful on the explanatory level. This includes two aspects: the first one is that the hypothesis should be broad and thus explain as much of the evidence as possible, and the other aspect is that it must also have depth, and therefore be further explained by other strong arguments or hypothesis.