Collecting information reported by imperfect information sources

Abstract

This paper studies how an agent can believe a new piece of information, not only when it is directly provided by another agent but also when it is reported through an agent who cites a third one. Two models are presented, the first one in modal logic and the other one in the Theory of Evidence. They both consider as primitive two positive properties of agents: their ability of reporting true information and their ability of reporting only true information, as well as their negative counterparts i.e, their ability of reporting false information and their ability of reported only false information. © 2012 Springer-Verlag Berlin Heidelberg.