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International Encyclopedia of Systems and Cybernetics

2nd Edition, as published by Charles François 2004 Presented by the Bertalanffy Center for the Study of Systems Science Vienna for public access.

About

The International Encyclopedia of Systems and Cybernetics was first edited and published by the system scientist Charles François in 1997. The online version that is provided here was based on the 2nd edition in 2004. It was uploaded and gifted to the center by ASC president Michael Lissack in 2019; the BCSSS purchased the rights for the re-publication of this volume in 200?. In 2018, the original editor expressed his wish to pass on the stewardship over the maintenance and further development of the encyclopedia to the Bertalanffy Center. In the future, the BCSSS seeks to further develop the encyclopedia by open collaboration within the systems sciences. Until the center has found and been able to implement an adequate technical solution for this, the static website is made accessible for the benefit of public scholarship and education.

A B C D E F G H I J K L M N O P Q R S T U V W Y Z

VARIETY 1)2)

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1)"Given a set of elements… the number of elements that can be distinguished" (W.R. ASHBY, 1951, p.167).

2)"A measure of uncertainty or the amount of selection needed to remove the uncertainty" (G. PASK, 1960, p.116).

ASHBY explains: "Thus the set {gbcggc} has a variety of 3 letters… For many purposes the variety may be more conveniently measured by the logarithm of this number. If the logarithm is taken to base 2, the unit is the bit. The context will make clear whether the number or its logarithm is being used as measure" (Ibid).

Generally it is now understood that the measure of variety is expressed in bits. Using this base, a bit is the quantity of information needed to reduce uncertainty by half. (thus the connection between ASHBY's and PASK's definitions).

Variety as a concept may look deceptively trivial. However, a still quite simple system, as ASHBY's homeostat, with 4 elements and 25 different possible positions for each of them offers already a variety of 25, i.e. 390.625 combinations. Really complex system's variety overcomes our imagination and, in order to give them some definition, constraints become an absolute necessity.

Categories

  • 1) General information
  • 2) Methodology or model
  • 3) Epistemology, ontology and semantics
  • 4) Human sciences
  • 5) Discipline oriented

Publisher

Bertalanffy Center for the Study of Systems Science(2020).

To cite this page, please use the following information:

Bertalanffy Center for the Study of Systems Science (2020). Title of the entry. In Charles François (Ed.), International Encyclopedia of Systems and Cybernetics (2). Retrieved from www.systemspedia.org/[full/url]

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