Belief Revision I: The AGM Theory

AGM theory is the most influential formal account of belief revision. Nevertheless, there are some issues with the original proposal. In particular, Parikh has pointed out that completely irrelevant information may be affected in AGM revision. To remedy this, he proposed an additional axiom (P) aiming to capture (ir)relevance by a notion of syntax splitting. In this paper we generalize syntax splitting from logical sentences to epistemic states, a step which is necessary to cover iterated revision. The generalization is based on the notion of marginalization of epistemic states. Furthermore, we study epistemic syntax splitting in the context of ordinal conditional functions. Our approach substantially generalizes the semantical treatment of (P) in terms of faithful preorders recently presented by Peppas and colleagues.

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Knowing-it-all but still learning: Perceptions of one’s own knowledge and belief revision.

Developmental Psychology ◽

10.1037/dev0000433 ◽

2017 ◽

Vol 53 (12) ◽

pp. 2319-2332 ◽

Cited By ~ 1

Author(s):

Sara Hagá ◽

Kristina R. Olson

Keyword(s):

Belief Revision ◽

Learning Perceptions

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Children change their answers in response to neutral follow-up questions by a knowledgeable asker

10.31234/osf.io/g3ftq ◽

2019 ◽

Author(s):

Elizabeth Bonawitz ◽

Patrick Shafto ◽

Yue Yu ◽

Sophie Elizabeth Colby Bridgers ◽

Aaron Gonzalez

Keyword(s):

Social Learning ◽

Belief Revision ◽

Correct Answer ◽

New Information ◽

Common Practices ◽

Parent Child

Burgeoning evidence suggests that when children observe data, they use knowledge of the demonstrator’s intent to augment learning. We propose that the effects of social learning may go beyond cases where children observe data, to cases where they receive no new information at all. We present a model of how simply asking a question a second time may lead to belief revision, when the questioner is expected to know the correct answer. We provide an analysis of the CHILDES corpus to show that these neutral follow-up questions are used in parent-child conversations. We then present three experiments investigating 4- and 5-year-old children’s reactions to neutral follow-up questions posed by ignorant or knowledgeable questioners. Children were more likely to change their answers in response to a neutral follow-up question from a knowledgeable questioner than an ignorant one. We discuss the implications of these results in the context of common practices in legal, educational, and experimental psychological settings.

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