The MECHANICS OF CO‐ORDINATE INDEXING AND ITS RELATION TO OTHER INDEXING METHODS

Co‐ordinate (sometimes called synthetic) indexing was in use for many years before it gained its present names. It had no name at all: it was simply the way people went about answering certain sorts of question. It was used in accountancy, quality control, staff placement, medical record keeping, and municipal housing management—to take examples at random. It consisted, and it still consists, in collecting an appropriate set of items and recording their features in a standard language, usually a code, on suitable data vehicles, usually cards. Each card represented an item, and was marked with coloured tabs, or punched with holes, or clipped around its edges, the tabs or holes or notches showing which features the item possessed. All items possessing any given set of features then became easy to find. One looked—one still looks—for the right set of tabs or notches or holes.