Combined grouping for coordinate indexes
Peter G. Perry · American Documentation · 1968
Abstract A method is suggested for the more economical storage of documents in coordinate indexes on the basis of inclusion relationships existing between sets of features assigned to documents. Essentially, the technique consists of using sets of features to identify documents that have been indexed either by all or by only some of the total features of the sets. The resulting index has been named a combined grouped coordinate index. Using combined grouping in the construction of a punched feature card index, the Group Research and Development Centre of E. S. & A. Robinson (Holdings) Ltd., Bristol, England, has achieved a 35% saving in dedicated positions. The advantages, implications, and applications of combining groups of features in coordinate indexes are discussed.