Chapitre D'ouvrage Année : 1998

Introduction: Revising, Updating and Combining Knowledge

Résumé

The question of knowledge base dynamics is currently one of the most challenging problems in the area of intelligent information systems. A change operation, sometimes also called revision, sometimes called update, consists in modifying the contents of a body of knowledge upon the arrival of some new piece of information. What is called ‘a body of knowledge’ can take several forms ranging from the contents of a database to the ill-known values of parameters, or a set of constraints incompletely describing a situation. In this book, knowledge is supposed to refer to a set of logical sentences, or to some uncertainty function on a set of alternatives, in each case representing the beliefs of an agent on a question of interest. The belief change literature has developed rather independently in two clusters corresponding to these two modes of representation of epistemic states. The oldest established belief revision theory is based on Bayes’ rule for probability measures. The study of change in probability theory has been dubbed ‘probability kinematics’ [Domotor, 1985], and is relevant to fields such as statistics, decision theory and philosophy of science. The logical framework has emerged with the advent of information systems and artificial intelligence. In the field of database research the problem of change naturally arises whenever the database is supposed to evolve: how to add a piece of information? what to do if the new information contradicts the already stored information? The latter problem cannot always be solved just by rejecting the new information. In the field of artificial intelligence the change problem is closely related to two issues that share a lot of concerns: how to handle the defeasibility of conclusions derived from exception-prone knowledge? How to reason about dynamic worlds? These issues question the monotonicity property of classical logic inference that excludes defeasibility, and have close connections with topics such as hypothetical reasoning, truth-maintenance systems and the theories of action.

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Dates et versions

hal-04030474 , version 1 (15-03-2023)

Identifiants

Citer

Didier Dubois, Henri Prade. Introduction: Revising, Updating and Combining Knowledge. Didier Dubois; Henri Prade. Belief Change, 3, Springer Netherlands, pp.1-15, 1998, Handbook of Defeasible Reasoning and Uncertainty Management Systems book series (HAND), 978-94-010-6123-0. ⟨10.1007/978-94-011-5054-5_1⟩. ⟨hal-04030474⟩
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