Editing Systems theory (section)

==System types and fields==

===Theoretical fields===
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{{Main|List of types of systems theory}}
* [[Chaos theory]]
* [[Complex system]]
* [[Control theory]]
* [[Dynamical systems theory]]
* [[Earth system science]]
* [[Ecological systems theory]]
* [[Industrial ecology]]
* [[Living systems theory]]<ref name=":7">{{cite book |doi=10.1016/B978-0-12-375000-6.00323-2 |chapter=Sex Roles |title=Encyclopedia of Human Behavior |date=2012 |last1=Sinnott |first1=J.D. |last2=Rabin |first2=J.S. |pages=411–417 |isbn=978-0-08-096180-4 }}</ref>
* [[Sociotechnical system]]
* [[Systemics]]
* [[Telecoupling]]
* [[Urban metabolism]]
* [[World-systems theory]]

====Cybernetics====
{{Main|Cybernetics}}

[[Cybernetics]] is the study of the [[communication]] and control of regulatory [[feedback]] both in living and lifeless systems (organisms, organizations, machines), and in combinations of those. Its focus is how anything (digital, mechanical or biological) controls its behavior, processes information, reacts to information, and changes or can be changed to better accomplish those three primary tasks.

The terms ''systems theory'' and ''cybernetics'' have been widely used as synonyms. Some authors use the term ''cybernetic'' systems to denote a proper subset of the class of general systems, namely those systems that include [[feedback loops]]. However, [[Gordon Pask]]'s differences of eternal interacting actor loops (that produce finite products) makes general systems a proper subset of cybernetics. In cybernetics, complex systems have been examined mathematically by such researchers as [[W. Ross Ashby]], [[Norbert Wiener]], [[John von Neumann]], and [[Heinz von Foerster]].

Threads of cybernetics began in the late 1800s that led toward the publishing of seminal works (such as Wiener's ''[[Cybernetics: Or Control and Communication in the Animal and the Machine|Cybernetics]]'' in 1948 and [[Ludwig von Bertalanffy|Bertalanffy]]'s ''General System Theory'' in 1968). Cybernetics arose more from engineering fields and GST from biology. If anything, it appears that although the two probably mutually influenced each other, cybernetics had the greater influence. Bertalanffy specifically made the point of distinguishing between the areas in noting the influence of cybernetics:<blockquote>Systems theory is frequently identified with cybernetics and control theory. This again is incorrect. Cybernetics as the theory of control mechanisms in technology and nature is founded on the concepts of information and feedback, but as part of a general theory of systems.... [T]he model is of wide application but should not be identified with 'systems theory' in general ... [and] warning is necessary against its incautious expansion to fields for which its concepts are not made.<ref name="GST" />{{Rp|17–23}}</blockquote>Cybernetics, [[catastrophe theory]], [[chaos theory]] and [[Complex systems#Complexity and chaos theory|complexity theory]] have the common goal to explain complex systems that consist of a large number of mutually interacting and interrelated parts in terms of those interactions. [[Cellular automaton|Cellular automata]], [[neural network]]s, [[artificial intelligence]], and [[artificial life]] are related fields, but do not try to describe general (universal) complex (singular) systems. The best context to compare the different "C"-Theories about complex systems is historical, which emphasizes different tools and methodologies, from [[pure mathematics]] in the beginning to pure [[computer science]] today. Since the beginning of chaos theory, when [[Edward Lorenz]] accidentally discovered a [[strange attractor]] with his computer, computers have become an indispensable source of information. One could not imagine the study of complex systems without the use of computers today.

===System types===
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* [[Biological system|Biological]]
** [[Anatomy|Anatomical systems]]
*** [[Nervous system|Nervous]]
**** [[Sensory system|Sensory]]
** [[Social ecological model#Bronfenbrenner's ecological framework for human development|Ecological systems]]
** [[Living systems]]
* [[Complex system|Complex]]
** [[Complex adaptive system]]
* [[Conceptual system|Conceptual]]
** [[Coordinate system|Coordinate]]
** [[Deterministic system (philosophy)|Deterministic]] (philosophy)
** [[Digital ecosystem]]
** [[Experimental system|Experimental]]
** [[Writing system|Writing]]
* [[Coupled human–environment system|Coupled human–environment]]
* [[Database system|Database]]
* [[Deterministic system|Deterministic]] (science)
* [[Mathematical system theory|Mathematical]]
** [[Dynamical system]]
** [[Formal system]]
* [[Energy system|Energy]]
* [[Holarchical System|Holarchical]]
* [[Information system|Information]]
* [[System of measurement|Measurement]]
** [[Imperial System|Imperial]]
** [[Metric system|Metric]]
* [[Multi-agent system|Multi-agent]]
* [[Nonlinear system|Nonlinear]]
* [[Operating system|Operating]]
* [[Planetary system|Planetary]]
* [[Social system|Social]]
** [[Cultural system|Cultural]]
** [[Economic system|Economic]]
** [[List of national legal systems|Legal]]
** [[Political system|Political]]
* [[Star system|Star]]

====Complex adaptive systems====
{{Main|Complex adaptive system}}
Complex adaptive systems (CAS), coined by [[John Henry Holland|John H. Holland]], [[Murray Gell-Mann]], and others at the interdisciplinary [[Santa Fe Institute]], are special cases of [[complex system]]s: they are ''complex'' in that they are diverse and composed of multiple, interconnected elements; they are ''adaptive'' in that they have the capacity to change and learn from experience.

In contrast to [[control system]]s, in which [[negative feedback]] dampens and reverses disequilibria, CAS are often subject to [[positive feedback]], which magnifies and perpetuates changes, converting local irregularities into global features.