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Taxonomy is the practice and science of classification. The word finds its roots in the Greek τάξις, taxis (meaning 'order', 'arrangement') and νόμος, nomos ('law' or 'science'). Taxonomy uses taxonomic units, known as taxa (singular taxon).

In addition, the word is also used as a count noun: a taxonomy, or taxonomic scheme, is a particular classification ("the taxonomy of ..."), arranged in a hierarchical structure. Typically this is organised by subtype-supertype relationships, also called parent-child relationships. In such a subtype-supertype relationship the subtype kind of thing has by definition the same constraints as the supertype kind of thing plus one or more additional constraints. For example, car is a subtype of vehicle. So any car is also a vehicle, but not every vehicle is a car. Therefore, a thing needs to satisfy more constraints to be a car than to be a vehicle.


[edit] Applications

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 be then 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 seen as less broad than ontologies as 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 form the specific to the more general.[5]

[edit] Taxonomy and mental classification

Some have argued that the adult human mind naturally organizes its knowledge of the world into such systems. This view is often based on the epistemology of Immanuel Kant. Anthropologists have observed that taxonomies are generally embedded in local cultural and social systems, and serve various social functions. Perhaps the most well-known and influential study of folk taxonomies is Émile Durkheim's The Elementary Forms of Religious Life.

[edit] Various taxonomies

Biological classification (sometimes known as "Linnaean taxonomy") is still generally the best known form of taxonomy. It uses taxonomic ranks, including, among others, (in order) Kingdom, Phylum, Class, Order, Family, Genus, Species (various mnemonic devices have been used to help people remember the list of "Linnaean" taxonomic ranks. See Zoology mnemonic). In zoology, the nomenclature for the more important ranks (superfamily to subspecies), including the allowed number of ranks, is strictly regulated by the ICZN Code, whereas there is more latitude for names at higher ranks. Taxonomy itself is never regulated, but is always the result of research in the scientific community. How researchers arrive at their taxa varies; depending on the available data, and resources, methods vary from simple quantitative or qualitative comparisons of striking features to elaborate computer analyses of large amounts of DNA sequence data.

Today, the alternative to the traditional rank-based biological classification is phylogenetic systematics (or "cladism"), which is based on cladistic analyses exclusively, to yield a taxonomy reproducing the phylogenetic tree. In cladism, taxa must always correspond to clades, which are discovered by analysis of apomorphies (derived traits). The results are often represented as cladograms. By comparison, although clades may be (and today usually are) used as a basis for ranked taxa, there is no formal requirement for rank-based taxonomy to correspond to the phylogenetic tree. The PhyloCode is a proposed formal ruleswork for a phylogenetic taxonomy, similar to the ICZN Code, ICBN etc. in rank-based nomenclature.

In numerical taxonomy, numerical phenetics or taximetrics, the taxonomy is exclusively based on cluster analysis and neighbor joining to best-fit numerical equations that characterize all measurable traits of a number of organisms. It results in a measure of evolutionary "distance" between species, averaged over all traits considered. This method has been largely superseded by cladistic analyses today; it is liable to being misled by plesiomorphic traits, which in phenetics are given equal weight to apomorphies.

[edit] Non-scientific taxonomies

Other taxonomies, such as those analyzed by Durkheim and Lévi-Strauss, are sometimes called folk taxonomies to distinguish them from scientific taxonomies that focus on evolutionary relationships rather than similarity in habitus and habits. Though phenetics arguably places much emphasis on overall similarity, it is a quantitative analysis that attempts to reproduce evolutionary relationships of lineages and not similarities of form taxa.

The neologism folksonomy should not be confused with "folk taxonomy", though it is obviously a portmanteau created from the two words. "Fauxonomy" (from French faux, "false") is a pejorative neologism used to criticize folk taxonomies for their lack of agreement with scientific findings. Baraminology is a taxonomy used in creation science which in classifying form taxa resembles folk taxonomies.

The phrase "enterprise taxonomy" is used in business to describe a very limited form of taxonomy used only within one organization. An example would be a certain method of classifying trees as "Type A", "Type B" and "Type C" used only by a certain lumber company for categorising log shipments.

[edit] Military taxonomy

Military theorist Carl von Clausewitz stressed the significance of grasping the fundamentals of any situation in the "blink of an eye" (coup d'œil). In a military context, the astute tactician can immediately grasp a range of implications and can begin to anticipate plausible and appropriate courses of action.[6] Clausewitz' conceptual "blink" represents a tentative ontology which organizes a set of concepts within a domain.

The term "military taxonomy" encompasses the domains of weapons, equipment, organizations, strategies, and tactics.[7] The use of taxonomies in the military extends beyond its value as an indexing tool or record-keeping template[8] -- for example, the taxonomy-model analysis suggests a useful depiction of the spectrum of the use of military force in a political context. [9]

A taxonomy of terms to describe various types of military operations is fundamentally affected by the way all elements are defined and addressed -- not unlike framing. For example, in terms of a specific military operation, a taxonomic approach based on differentiation and categorization of the entities participating would produce results which were quite different from an approach based on functional objective of an operation (such as peacekeeping, disaster relief, or counter-terrorism).[10]

[edit] Notes

  1. ^ Zirn, Cäcilia, Vivi Nastase and Michael Strube. "Distinguishing Between Instances and Classes in the Wikipedia Taxonomy" (paper); (video lecture). 5th Annual European Semantic Web Conference (ESWC 2008).
  2. ^ Jackson, Joab. "Taxonomy’s not just design, it’s an art," Government Computer News (Washington, D.C.). September 2, 2004.
  3. ^ Suryanto, Hendra and Paul Compton. "Learning classification taxonomies from a classification knowledge based system." University of Karlsruhe; "Defining 'Taxonomy'," Straights Knowledge website.
  4. ^ Malone, Joseph L. (1988). The Science of Linguistics in the Art of Translation: Some Tools from Linguistics for the Analysis and Practice of Translation, p. 112.
  5. ^ Grossi, Davide, Frank Dignum and John-Jules Charles Meyer. (2005). "Contextual Taxonomies" in Computational Logic in Multi-Agent Systems, pp. 33-51.
  6. ^ Calusewitz, Carl. (1982). On War, p. 141; "Defining 'Taxonomy'," Straights Knowledge website.
  7. ^ Cycorp: Structured information
  8. ^ Fenske, Russell W. "A Taxonomy for Operations Research," Operations Research, Vol. 19, No. 1 (Jan.-Feb., 1971), pp. 224-234;] United Nations. "Taxonomy for Recordkeeping in Field Missions of UN Peacekeeping Operations." June 2006.
  9. ^ Cohen, Stuart A. and Efraim Inbar. "A taxonomy of Israel's use of military force," Journal Comparative Strategy, Vol. 10, No. 2 (April 1991), pp. 121 - 138.
  10. ^ Downie, Richard D. "Defining integrated operations," Joint Force Quarterly (Washington, D.C.). July, 2005.

[edit] References

[edit] See also

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