A Look Back and a Look Forward

This paper is in two parts, following the suggestion that I first comment on my own past experience in information retrieval, and then present my views on the present and future. Some personal history I began serious work in IR in the mid sixties through one of those funding accidents that afflict everyone in research; but I had become involved with it before that, for respectable intellectual reasons. The group working under Margaret Masterman at the Cambridge Language Research Unit had argued for the use of a thesaurus as a semantic interlingua in machine translation, and had then seen that a thesaurus could be used in a similar way, as a normalising device, for document indexing and retrieval (Masterman et al 1958). My doctoral research was concerned with automatic methods of constructing thesauri for language interpretation and generation in tasks like machine translation; and Roger Needham was working at the same time on text-based methods of constructing retrieval thesauri, in the context of research on general-purpose automatic classification techniques. The essential common idea underlying this work was that word classes, defining lexical substitutibility, could be derived by applying formal clustering methods to word occurrence,