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.


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.


NOISE in a channel 5)

Any random disturbance originated in the environment which reduces the reliability of a message transmission in a communication channel.

SHANNON'S so-called 10 Theorem states: "If noise appears in a message, the amount of noise that can be removed by a correction channel is limited to the amount of information that can be carried by the channel

This is quite similar to ASHBY's "Law of Requisite Variety"

Many practical examples are well known, for example in radio, T.V., telephone, fax, etc… transmission.

K. KRIPPENDORFF comments: "The analogy between noise and thermodynamic entropy is suggested by the fact that in any communication process, noise can only increase and it does so at the expense of the amount of information transmitted from a sender to one or more receivers" (1986, p.53).

In some cases, noise disturbances may endanger the functional reliability of parts or even the whole of a system: a lightning may put an electric circuit out of order, or a jumbled message may impair some critical action.

R.L. ACKOFF and F.E. EMERY distinguish semantic, syntactic and pragmatic noise. On this last they write: "Pragmatic noise (is) anything that appears in a message or its environment that was not produced by the sender and decreases the probability of the receiver's responding in the way intended by the sender" (1972, p.182).

T.F.H. ALLEN and T.B. STARR go further and define noise as "Any aspect of a signal string which is not considered significant" (1982, p.274)

Or: "That part of the signal which is not considered to be associated with meaning for the purpose at hand" (Ibid).

The word "considered" introduce (rightly) a doubt, as in this case, either the sender, or the receiver – or both – may well miss something significant in the message only because they do not consider it – or simply do not understand it – to be significant!

It must however be admitted that "significance" is a characteristic of the observer, which moreover, may subtly depend on her/his interpretative ability. BECQUEREL's veiled photographic plates where spoiled by "noise", until he did understood the correlation with the (radioactive) samples that he had stored in the same drawer, without noticing their peculiar behavior.


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


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]

We thank the following partners for making the open access of this volume possible: