Analysing reasoning about evidence with formal models of argumentation

Abstract

This paper is on the formal modelling of reasoning about evidence. The main purpose is to advocate logical approaches as a worthwhile alternative to approaches rooted in probability theory. In particular, the use of logics for defeasible argumentation is investigated. Such logics model reasoning as the construction and comparison of arguments for and against a conclusion; this makes them very suitable for capturing the adversarial aspects that are so typical for legal evidential reasoning. Also, it will be shown that they facilitate the explicit modelling of different kinds of knowledge, such as the distinction between direct vs. ancillary evidence, and the explicit modelling of different types of evidential arguments, such as appeals to witness or expert opinion, applying generalizations, or temporal projections.