Explanation
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
http://en.wikipedia.org/wiki/cybernetics