Eur. Phys. J. B (2012) 85: 44
https://doi.org/10.1140/epjb/e2011-20617-8

Regular Article

Probability of inconsistencies in theory revision^*

A multi-agent model for updating logically interconnected beliefs under bounded confidence

¹ University of Groningen, Faculty of Philosophy, Oude Boteringestraat 52, 9712 GL Groningen, The Netherlands
² Ghent University, Department of Inorganic and Physical Chemistry, Krijgslaan 281 – S3, 9000 Gent, Belgium

^a e-mail: s.wenmackers@rug.nl

Received: 26 July 2011
Received in final form: 26 November 2011
Published online: 25 January 2012

Abstract

We present a model for studying communities of epistemically interacting agents who update their belief states by averaging (in a specified way) the belief states of other agents in the community. The agents in our model have a rich belief state, involving multiple independent issues which are interrelated in such a way that they form a theory of the world. Our main goal is to calculate the probability for an agent to end up in an inconsistent belief state due to updating (in the given way). To that end, an analytical expression is given and evaluated numerically, both exactly and using statistical sampling. It is shown that, under the assumptions of our model, an agent always has a probability of less than 2% of ending up in an inconsistent belief state. Moreover, this probability can be made arbitrarily small by increasing the number of independent issues the agents have to judge or by increasing the group size. A real-world situation to which this model applies is a group of experts participating in a Delphi-study.