Taken by surprise: the paradox of the surprise test revisited
type: Item
instance of: scholarly article
title: Taken by surprise: the paradox of the surprise test revisited
zbMATH Open document ID: 0614.03005
DOI: 10.1007/BF00248573
author: Joseph Y. Halpern
author: Yoram Moses
published in: Journal of Philosophical Logic
publication date: 1986-01-01T00:00:00Z
review text: This paper analyses the surprise exam paradox. It gives four formulations, each of which remedies what may be taken to be a defect in a prior formulation. In the final version, the information provided by the teacher turns out to be genuinely paradoxical (consistent and inconsistent). The informal analyses are supported by translation into a theory in a language with provability and fixed point operators. A semantics for the language is provided, and the theory is proved sound with respect to it. As an analysis of the paradox the approach is rather dubious. For it supposes ''knows'' to mean ''is provable from the information provided''. But this assumes that the information is known to be true, which, arguably, is exactly what the paradox shows to be false. The paper can, however, be seen as supporting this conclusion. For if the information is known to be correct then the supposition is a reasonable one in the context, and, as the paper then shows, a most plausible interpretation of the situation ends up in a knot.
Mathematics Subject Classification ID: 03A05
zbMATH DE Number: 3993531
zbMATH Keywords: paradox of surprise examination
zbMATH Keywords: provability
zbMATH Keywords: fixed point operators
zbMATH Keywords: semantics
reviewed by: Graham Priest
MaRDI profile type: Publication
description: scientific article; zbMATH DE number 3993531