Yves Moinard Notes on Change and Nonmonotony , Série Revision and Updating in Knowledge Bases. , Wiley , 101--118 , 1994 Abstract Theories of change and nonmonotonic formalisms originated from the same knowledge representation problems. The differences in their respective aims and methods are illustrated by a comparison between the possible model approach and preferential entailment. Then, one technical way of using a nonmonotonic formalism in order to achieve cognitive change is shortly described, and the same for the other way around. the more philosophically oriented two way passage by Gardenfors and Makinson is then examined at length, including the newest versions providing a general translation through epistemic entrenchment. Some kind of ``concretization'' of these theoretical considerations are then described. Finally, thanks to the Gardenfors and Makinson's passage, we translate some important criteria for belief revision into nonmonotony. This general comparison provides as many insights on the nonmonotonic side as on the cognitive change side. This web site is maintained by René Quiniou using the Weave system from the Caravel project: http://www-caravel.inria.fr. Last modification: 10-07-2011 09:54:25