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