Taxonomy is the practice and science of classification. The word comes from the Greek "Polytonic|τάξις", "taxis" (meaning 'order', 'arrangement') and "Polytonic|νόμος", "nomos" ('law' or 'science'). Taxonomies, or taxonomic schemes, are composed of "taxonomic units" known as "taxa" (singular "
taxon"), or kinds of things that are arranged frequently in a hierarchicalstructure. Typically they are related 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.
Originally the term taxonomy referred to the classifying of living organisms (now known as
alpha taxonomy); however, the term is now applied in a wider, more general sense and now may refer to a "classification" of things, as well as to the "principles" underlying such a classification.
Almost anything — animate objects, inanimate objects, places, concepts, events, properties, and relationships — may be classified according to some taxonomic scheme. Wikipedia categories illustrate a taxonomy
schema. [Zirn, Cäcilia, Vivi Nastase and Michael Strube. [http://www.eswc2008.org/final-pdfs-for-web-site/onl-4.pdf "Distinguishing Between Instances and Classes in the Wikipedia Taxonomy" (paper);] [http://videolectures.net/eswc08_tenerife/ (video lecture).] 5th Annual European Semantic Web Conference(ESWC 2008).]
The term taxonomy may also apply to relationship schemes other than parent-child hierarchies, such as network structures with other types of relationships. Taxonomies may 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. [Jackson, Joab. [http://www.gcn.com/print/23_3/24814-1.html?topic=interview&page=2 "Taxonomy’s not just design, it’s an art,"] "Government Computer News" (Washington, D.C.). September 2, 2004.]
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. [Suryanto, Hendra and Paul Compton. [http://ol2000.aifb.uni-karlsruhe.de/final/HSuryanto_5.pdf "Learning classification taxonomies from a classification knowledge based system."] University of Karlsruhe; [http://www.greenchameleon.com/gc/blog_detail/defining_taxonomy/ "Defining 'Taxonomy',"] Straights Knowledge website.]
Mathematically, a hierarchical taxonomy is a
tree structureof 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. So for instance, in common schemes of scientific classificationof organisms, the root is called " Organism" followed by nodes for the taxonomic ranks: Domain, kingdom, phylum, class, etc. The progress of reasoning proceeds from the general to the more specific.
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. [Grossi, Davide, Frank Dignum and John-Jules Charles Meyer. (2005). [http://www.springerlink.com/content/9yj2lfa5cy67c78m/fulltext.pdf?page=1 "Contextual Taxonomies" in "Computational Logic in Multi-Agent Systems," pp. 33-51] .]
Taxonomy and mental classification
Some have argued that the human mind naturally organizes its knowledge of the world into such systems. This view is often based on the
epistemologyof 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".
Linnaean taxonomyis the system most familiar to non-taxonomists. It uses the formal taxonomic ranks (in order) Kingdom, Phylum, Class, Order, Family, Genus, Species. The lower ranks ( superfamilyto subspecies) are strictly regulated, e.g. by the ICZNfor animals, whereas taxonomy at higher ranks is a result of consensus in the scientific community. How researchers arrive at their taxa varies; depending on the available data and resources; methods vary from simple qualitativecomparisons for little-documented organisms to elaborate cladisticanalyses for well-known groups with abundant DNA sequencedata.
phylogenetic taxonomy, cladistic taxonomy or cladism, organisms are classified into " clades", which are discovered by grouping taxa using derived traits. By using clades as the criteria for separation, cladistic taxonomy, using cladograms, can categorize taxa into unranked groups. The taxonomy is exclusively based on cladisticanalysis.
In numerical taxonomy,
pheneticsor taximetrics, the taxonomy is exclusively based on cluster analysisand neighbor joiningto best-fit numerical equations that characterize all measurable quantities of a number of organisms. This method has been largely superseded by the superior cladistic analyses today, except in cases when these are too computationally intensive (a single large-scale cladistic analysis can take months to compute).
Other taxonomies, such as those analyzed by
Durkheimand Lévi-Strauss, are sometimes called folk taxonomies to distinguish them from scientific taxonomies that focus on evolutionary relationships rather than similarity in habitusand habits. Though phenetics arguably places much emphasis on overall similarity, it is a quantitative analysis that attempts to reproduce evoultionary relationships of lineages and not similarities of form taxa.
neologism folksonomyshould not be confused with "folk taxonomy", though it is obviously a contraction of the two words. "Fauxonomy" (from French "faux", "false") is a pejorative neologismused to criticize folk taxonomies for their lack of agreement with scientific findings. Baraminologyis a taxonomy used in creation sciencewhich 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.
Carl von Clausewitzstressed 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. [Calusewitz, Carl. (1982). [http://books.google.com/books?id=_La4qTgECD0C&pg=PA141&lpg=PA141&dq=clausewitz+coup+d%27oeil&source=web&ots=8UCKTI28o4&sig=0ntr9cQoagmpsJVuulXii533H8U&hl=en&sa=X&oi=book_result&resnum=10&ct=result "On War," p. 141;] [http://www.greenchameleon.com/gc/blog_detail/defining_taxonomy/ "Defining 'Taxonomy',"] Straights Knowledge website.]
The term "
military taxonomy" encompasses the domains of weapons, equipment, organizations, strategies, and tactics.Cycorp: [http://www.cyc.com/products/overview Structured information] ] The use of taxonomies in the military extends beyond its value as an indexing tool or record-keeping template. [Fenske, Russell W. [http://www.jstor.org/pss/168881 "A Taxonomy for Operations Research,"] "Operations Research," Vol. 19, No. 1 (Jan.-Feb., 1971), pp. 224-234;] United Nations. [http://archives.un.org/unarms/doc/taxonomy/20060609_Taxonomy_-_Version_1.pdf "Taxonomy for Recordkeeping in Field Missions of UN Peacekeeping Operations."] June 2006. ] In the 21st century, the ambit of a subset taxonomy of terrorism would include terms related to terrorists, terrorist groups, terrorist attacks, weapons, venues, and characteristics of terrorists and terrorist groups.
A taxonomy of terms to describe various types of military operations is fundamentally affected by the way in 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). An incidental advantage which flows from give-and-take in refining taxonomic terms more accurately and efficiently becomes more than a worthwhile objective in terms of anticipated outcomes or results. In today's nontraditional operations, the discussion about fundamentals also generates greater precision in how the defense and security community understands and discusses integrated operations. [Downie, Richard D. [http://findarticles.com/p/articles/mi_m0KNN/is_38/ai_n15631260/pg_3?tag=artBody;col1 "Defining integrated operations,"] "Joint Force Quarterly" (Washington, D.C.). July, 2005.]
A number of military strategies can be parsed using a taxonomy model. The comparative theoretical framework might posit a range of criteria, e.g., the character of envisaged political goals, the type of military strategy preferred, and the scope of forces engaged; and this template suggests discrete modes of force. The taxonomy-model analysis suggests a useful depiction of the spectrum of the use of military force in a political context. [Cohen, Stuart A. and Efraim Inbar. [http://www.informaworld.com/smpp/content~content=a782379359~db=all~order=page "A taxonomy of Israel's use of military force,"] "Journal Comparative Strategy," Vol. 10, No. 2 (April 1991), pp. 121 - 138.]
* Carbonell, J. G. and J. Siekmann, eds. (2005). [http://www.springerlink.com/content/fb5lq38pu0c7/?p=55d6f2e6622046f5909b8b3d31994ddb&pi=0 "Computational Logic in Multi-Agent Systems," Vol. 3487.] Berlin:
Springer-Verlag. 13-ISBN 978-3-540-28060-6
* Clausewitz, Carl. (1982). [http://books.google.com/books?id=_La4qTgECD0C&dq=clausewitz+coup+d%27oeil&source=gbs_summary_s&cad=0 "On War"] (editor, Anatol Rapoport). New York:
Penguin Classics. 10-ISBN 0-140-44427-0; 13-ISBN 978-0-140-44427-8
Carolus Linnaeus, the father of systematics
Celestial Emporium of Benevolent Recognition, a fictional Chinese encyclopedia with an "impossible" taxonomic scheme.
Cladistics, the most prominent of several forms of phylogenetic systematics
Gellish English dictionary/ Taxonomy, in which the concepts are arranged as a subtype-supertype hierarchy.
History of plant systematics
* [http://www.db.dk/jni/lifeboat/info.asp?subjectid=15 Hjørland: Scientific classification and taxonomy. IN: The epistemological Lifeboat]
* [http://brainpath.wordpress.com/2007/02/07/7/ Utter freedom via tagging and social constructs]
* [http://species.wikimedia.org/ Wikispecies Main Page]
* [http://www.itis.gov/ Integrated Taxonomic Information System]
* [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi/ Taxonomy Browser of National Center for Biotechnology Information]
* [http://www.taxonomystrategies.com/html/bibliography.htm Library of Taxonomy Resources]
* [http://www.ontopia.net/topicmaps/materials/tm-vs-thesauri.html Metadata? Thesauri? Taxonomies? Topic Maps! - Making sense of it all]
* [http://www.taxonomies-sig.org/ Taxonomies & Controlled Vocabularies Special Interest Group of the American Society for Indexing]
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