Bierlaire, Michel2008-02-152008-02-152008-02-152007https://infoscience.epfl.ch/handle/20.500.14299/18726This short document contains lecture notes of an invited plenary lecture made during the conference ``Metodi, modelli e tecnologie dell'informazione a supporto delle decisioni'', organized by Università di Napoli Federico II on September 30, 2006, on the island of Procida, Italy.text::report