A method for updating that justifies minimum cross entropy

Abstract

Given a general knowledge base about a population of individuals, we consider the problem of applying, or updating, that general knowledge to reason about a particular individual from the population about whom we have only some partial and uncertain information. We show that given an inference process for reasoning about the general knowledge, this process yields a natural and justifiable method of updating to knowledge about a particular individual. In particular, we show that in the case of the maximum entropy inference process this yields minimum cross entropy updating. We also consider several other updating procedures arising in this way.