Cybernetics is the scientific study of how people, animals, and machines control and communicate information (for example, via feedback loops). Control mechanisms according to cybernetic principles, are also found in genetic evolutionary processes, as well as in the emergence and development of ecosystems.

Cybernetics investigates and describes the regulation and control in animals (including humans), in organizations, and in machines when they are viewed as self-governing whole entities, consisting of parts and their dynamic organization.

Cybernetics views communication and control in all self-contained complex systems as analogous. It differs from the empirical sciences (physics, biology, etc.) in not being interested in material form but in organization, pattern, and communication in entities. Because of the increasing sophistication of computers and the efforts to make them behave in humanlike ways, cybernetics today is closely allied with artificial intelligence and robotics, and it draws heavily on ideas developed in information theory.

Law of Requisite Variety

The total amount of cybernetic knowledge deposited within a system is related to the total number of different states that the system can assume while interacting with the environment. This is referred to as the cybernetic variety of the system. The demands on variety are determined by Ashby’s Law of Requisite Variety (Ashby 1958; Beer 1974), which states:
"For a successful control of a system, the system that controls has to have at least as many states as the system being controlled."
Thus, being a good model of the environment entails a sufficient number of states, which is a pre-requirement to store a sufficient amount of cybernetic knowledge within the systems.
Generally speaking: Knowledge requires variety.

Good Regulator Theorem

Cybernetic knowledge is necessarily subjected to Conant & Ashby’s Good Regulator Theorem (Conant & Ashby 1970), stating:
“Any successful control mechanism must be a model of the system that it controls”.
That is, one can deal with the surrounding world successfully only if one already possesses certain knowledge about the effects that one’s actions are likely to exert on that world.
Maturana and Varela (1980, 1992) expressed it as: 
“All doing is knowing and all knowing is doing.”

Historical Frame

The concept of cybernetic was conceived by Norbert Wiener, who coined the term in 1948.

Linguistic derivation

The term Cybernetics is derived from the Ancient Greek words kybernetes meaning "pilot", "governor"; or from kybernan = "to steer", "to govern". 

External sources


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