feedback
Feedback occurs when outputs of a system are “fed back” as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to “feed back” into itself. The notion of ’cause-and-effect’ has to be handled carefully when applied to feedback systems: “Simple causal reasoning about a feedback system is difficult because the first system influences the second and second system influences the first, leading to a circular argument. This makes reasoning based upon cause and effect tricky, and it is necessary to analyze the system as a whole.” In this context, the term “feedback” has also been used as an abbreviation for: Feedback signal – the conveyance of information fed back from an output, or measurement, to an input, or effector, that affects the system. Feedback loop – the closed path made up of the system itself and the path that transmits the feedback about the system from its origin (for example, a sensor) to its destination (for example, an actuator). Negative feedback – the case where the fed-back information acts to control or regulate a system by opposing changes in the output or measurement.
