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Ashby's law

From Wiktionary, the free dictionary

English

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Alternative forms

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Etymology

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Originally formulated by the cyberneticist W. Ross Ashby in 1956.[1][2]

Proper noun

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Ashby's law

  1. To control variety externally, you must be able to control even more variety internally.
    • (Can we date this quote?), (Please provide the book title or journal name)[1]:
      His "Law" of Requisite Variety stated that for a system to be stable, the number of states that its control mechanism is capable of attaining (its variety) must be greater than or equal to the number of states in the system being controlled.

References

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  1. ^ Ashby, W. R. 1956, An Introduction to Cybernetics, Chapman & Hall, 1956, →ISBN (also available in electronic form as a PDF from Principia Cybernetica)
  2. ^ Ashby, W. R. 1958, Requisite Variety and its implications for the control of complex systems, Cybernetica (Namur) Vol. 1, No. 2, 1958.