PIs: Prof. Dr. Markus Knauff, PD Dr. Dr. Marco Ragni, Dr. Stefan Wölfl
Involved: Alexandra Varga, PhD
Institution: Justus-Liebig-Universität Gießen, Albert-Ludwigs-Universität Freiburg

Abstract
Logical frameworks of non-monotonic reasoning extend classical logics in order to justify defeasible conclusions from knowledge or belief bases. These logics aim at making explicit the rational core of commonsense reasoning, i.e., human reasoning in everyday situations. This project will be settled at the intersection of cognitive modeling of human reasoning and philosophical foundation of formal, non-monotonic logics. It will analyze the extent to which logical approaches of non-monotonic reasoning discussed in the literature allow for representing human deductive processes as well as the rationality criteria that underlie such processes. To do this, the project will conduct a series of cognitive studies on paradigmatic reasoning tasks such as the classical suppression tasks and newly developed tasks that will help to analyze consistency preservation in human reasoning. Based on the empirical findings we will develop a cognitive model of human deductive processes and analyze this cognitive model with regard to the previously determined rationality criteria. The cognitive model will be evaluated in further experiments to assess its predictive power for "rational" and "irrational" processes in human reasoning.