1. Using a classification scheme, which may be a coding system, commonly hierarchical and conceived as a tool to analyse a collection of data and establish their interrelationships.
2. The act or method of distributing properties or characteristics into groups, classes or families, resulting in a system of groups or a systematic division of a series of related phenomena.
The science of classification in a broad sense, although it is usually associated with biological classification and specifically the classification of plants and animals in hierarchies of superior and subordinate groups. Other subjects with taxonomic problems include: psychology, archaeology, sociology, linguistics, pattern recognition, and information storage and retrieval. In each case the aim is to reduce very large quantities of data to manageable proportions, by which is meant the ability to efficiently sort unit entries into categories.