The LOGIC OF CO‐ORDINATE INDEXING

The fundamental structure which is dealt with in all information handling is the data field—the set of things or items with which we are concerned, together with the set of qualities or features which make these of interest to us. It is an extremely important, and deceptively simple structure. Since co‐ordinate indexing forms a large part of information handling, we may deduce that its practitioners know a 'good deal about the data field in fact, no matter what they may think about its theory. Indeed, here as elsewhere facts come first and theories toddle after, explaining why we might have expected the behaviour which surprised us. The theoretician seems a professor of glorious hindsight, hoping that what he says will be helpful to people facing the other way.