A STATISTICAL ANALYSIS OF RETRIEVAL TESTS: A BAYESIAN APPROACH

A model is proposed to explain the retrieval characteristics of an IR system. It is assumed that, for a given system and a given question, there are probabilities of retrieving relevant or non‐relevant documents, but that these probabilities are not necessarily the same for different questions. A Bayesian method is outlined for estimating these probabilities, on the basis of a model relating them. The method is applied successfully to some Cranfield data. Potentialities of the method are discussed.