THRESHOLD
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(2) |
| ID | ◀ 3545 ▶ |
| Object type | General information |
The point on a curve of behavior where a systems function crosses the limit of its dynamic stability regime.
Below this limit the system's behavior is not fundamentally affected by excessive stimulations. Most generally, the various functions within a system are oscillating around a standard value. In such a case “… all states are equilibrial when some parameter function is less than a certain value, and few or none are equilibrial when it exceeds that value” (W.R. ASHBY, 1960, p.168).
The crossing of a stability threshold may either destroy the system, or transform it beyond recognition, within a process of emergence, and towards a different and frequently more complex level of organization.
A slightly different understanding of the threshold is “the minimum-required stimulation” to trigger a change in the organization of a network (J.von NEUMANN, 1958, p. 55).
In unstable composite systems or networks, a threshold defines the minimum constraint that must be applied in order to break the networks structure and start a global flow or an avalanche in the network, which may also lead to a reordering of its structure. Close to such a constraint threshold, a very small disturbance can start a considerable change.
In any case, the crossing of a threshold implies a discontinuity and a qualitative change. A threshold is a “point of no return” to the original conditions.