A Model for Generalization Based on Confirmatory Induction

Abstract

Confirmatory induction is based on the assumption that unknown individuals are similar to known ones, i.e. they satisfy the properties shared by known individuals. This assumption can be represented inside a non-monotonic logical framework. Accordingly, existing approaches to confirmatory induction take advantage of the machinery developed so far for non-monotonic inference. However, they are based on completion policies that are unnecessary strong for the induction purpose. The contribution of this paper is twofold: some basic requirements that any model for generalization based on confirmatory induction should satisfy are proposed. Then, a model for generalization based on Hempel's notion of confirmation is introduced. This model is rational in the sense that it satisfies the rationality postulates we exhibit; moreover, the completion principle on which this model is based captures exactly the similarity assumption, hence the model can be considered minimal as well.