1. A data handling device for organising and storing documents for subsequent retrieval, the documents having associated metadata terms, the device comprising: means configured to provide access to a store of existing metadata; means configured to analyse the existing metadata to generate statistical data as to co-occurrence of pairs of terms in the metadata of a single document; means configured to analyse a fresh document to assign to the fresh document a set of terms and configured to determine a measure of a strength of association of each term with the document; means configured to determine for each term of the set of terms a score that is a monotonically increasing function of (a) the strength of association with the document and of (b) a relative frequency of co-occurrence, in the existing metadata, of the term and another term that occurs in the set of terms; means configured to select, as metadata for the fresh document, a subset of the terms in the set of terms having highest scores.