This paper discusses research which was carried out at the Department of Information Studies, University of Sheffield in the period 1965 to 1985 into storage and retrieval techniques for databases of textual and chemical structure data. The research includes the development of methods for the automatic production of printed subject indexes and for the indexing and retrieval of chemical structures and chemical reactions, the variety generation method for the analysis, characterization and storage of data in a range of types of textual database, the prediction of biological activity in chemical compounds, and the design of document retrieval systems.the textual context [47]. In large part, these similarities of application arise from the frequency distributions underlying these two types of data, a factor which has become clear from the studies described in Sections 4 and 5 of tlus paper. This