Taxonomy is the practice and science of classification.
Originally the term taxonomy referred only to the classifying of organisms (now sometimes known as alpha taxonomy) or a particular classification of organisms. However, it has become fashionable in certain circles to apply the term in a wider, more general sense, where it may refer to a classification of things or concepts, as well as to the principles underlying such a classification.
Almost anything — animate objects, inanimate objects, places, concepts, events, properties, and relationships — may then be classified according to some taxonomic scheme. Wikipedia categories illustrate a taxonomy schema.[1]
In an even wider sense, the term taxonomy could also be applied to relationship schemes other than parent-child hierarchies, such as network structures with other types of relationships. Taxonomies may then include single children with multi-parents, for example, “Car” might appear with both parents “Vehicle” and “Steel Mechanisms”; to some however, this merely means that ‘car’ is a part of several different taxonomies.[2] A taxonomy might also be a simple organization of kinds of things into groups, or even an alphabetical list. However, the term vocabulary is more appropriate for such a list. In current usage within “Knowledge Management“, taxonomies are considered narrower than ontologies since ontologies apply a larger variety of relation types.[3]
Mathematically, a hierarchical taxonomy is a tree structure of classifications for a given set of objects. It is also named Containment hierarchy. At the top of this structure is a single classification, the root node, that applies to all objects. Nodes below this root are more specific classifications that apply to subsets of the total set of classified objects. The progress of reasoning proceeds from the general to the more specific. In scientific taxonomies, a conflative term is always a polyseme.[4]
In contrast, in a context of legal terminology, an open-ended contextual taxonomy—a taxonomy holding only with respect to a specific context. In scenarios taken from the legal domain, a formal account of the open-texture of legal terms is modeled, which suggests varying notions of the “core” and “penumbra” of the meanings of a concept. The progress of reasoning proceeds from the specific to the more general.[5]
side-note on metazoa: “if you separate out the things that only animals possess, what are you left with? …Extra-Cellular Matrix (ECM)
