Classification and its Structures
C. Michael Sperberg-McQueen · 2015
Classification is the grouping of objects into classes; the process is ubiquitous. A simple nominal classification simply assigns names to each class; ordinal classifications arrange classes in an order; more complex classifications arrange objects notionally in a multidimensional space. Some classification schemes define necessary and sufficient conditions for assignment to given classes; others group objects into clusters (with or without identifying exemplars which form the center of each cluster). Rules can be given which may encourage useful classification schemes, but in principle no single classification scheme can ever be exhaustive or meet all needs. For many practical needs, pre-existing classifications can sometimes be used; sometimes, however, no pre-existing system serves and needs can be met only by a new classification scheme.