We consider decision problems under complete ignorance and extend the minimax regret principle to situations where, after taking an action, the decision maker does not necessarily learn the state of the world. For example, if the decision maker only learns what the outcome is, then all she knows...

In an earlier paper [Rational choice andAGMbelief revision, Artificial Intelligence, 2009] a correspondence was established between the choice structures of revealed-preference theory (developed in economics) and the syntactic belief revision functions of the AGM theory (developed in philosophy...

We argue in favor of a departure from the standard equilibrium approach in game theory in favor of the less ambitious goal of describing only the actual behavior of rational players. We investigate the notion of rationality in behavioral models of extensive-form games (allowing for imperfect...

We consider a basic logic with two primitive uni-modal operators: one for certainty and the other for plausibility. The former is assumed to be a normal operator (corresponding - semantically - to a binary Kripke relation), while the latter is merely a classical operator (corresponding -...