# Hierarchy

A hierarchy (Greek: hierarchia (ἱεραρχία), from hierarches, "leader of sacred rites") is an arrangement of items (objects, names, values, categories, etc.) in which the items are represented as being "above," "below," or "at the same level as" one another. Abstractly, a hierarchy can be modelled mathematically as a rooted tree: the root of the tree forms the top level, and the children of a given vertex are at the same level, below their common parent.

A hierarchy (sometimes abbreviated HR) can link entities either directly or indirectly, and either vertically or horizontally. The only direct links in a hierarchy, insofar as they are hierarchical, are to one's immediate superior or to one of one's subordinates, although a system that is largely hierarchical can also incorporate alternative hierarchies. Indirect hierarchical links can extend "vertically" upwards or downwards via multiple links in the same direction, following a path. All parts of the hierarchy which are not linked vertically to one another nevertheless can be "horizontally" linked through a path by traveling up the hierarchy to find a common direct or indirect superior, and then down again. This is akin to two co-workers or colleagues; each reports to a common superior, but they have the same relative amount of authority. Organizational forms exist that are both alternative and complimentary to hierarchy. Heterarchy (sometimes abbreviated HT) is one such form.

### Other articles related to "hierarchy":

The Mesoamerican Maya Priesthood After The Conquest
... The priestly hierarchy disappeared in the wake of the Spanish Conquest ... In this town, a hierarchy of ‘mother-fathers’ is charged with the priestly tasks of prayer and sacrifice two of them on behalf of the town as a whole ... Besides this hierarchy, a large part of the population (about 10000) has been initiated as diviner (ajk’ij) ...
Hierarchy - Contexts and Applications - Methods Using The Hierarchical Model
... Analytic Hierarchy Process Hierarchical Decision Process Hierarchic Object-Oriented Design Hierarchical Bayes model Hierarchical clustering ...
Low And High Hierarchies
... the computational complexity theory, the low hierarchy and high hierarchy of complexity levels were introduced in 1983 by Uwe Schöning to describe the internal structure of the complexity class NP ... The low hierarchy starts from complexity class P and grows "upwards", while the high hierarchy starts from class NP and grows "downwards" ... On the other hand, if the low hierarchy consists of at least two levels, then P is not NP ...
Saint Ambrosii Of Belaya Krinitsa
... the Old Believers in 1846, thus establishing a full Church Hierarchy of the Old Believers ... This hierarchy became known as the Belokrinitskaya Hierarchy ...

### Famous quotes containing the word hierarchy:

In a hierarchy every employee tends to rise to his level of incompetence.
Laurence J. Peter (1919–1990)

In the world of the celebrity, the hierarchy of publicity has replaced the hierarchy of descent and even of great wealth.
C. Wright Mills (1916–1962)