Feedback

Feedback is a process in which information about the past or the present influences the same phenomenon in the present or future. As part of a chain of cause-and-effect that forms a circuit or loop, the event is said to "feed back" into itself.

Overview

Feedback is a mechanism, process or signal that is looped back to control a system within itself. This loop is called a feedback loop. Feedback loops can be either positive or negative. Positive feedback enhances or amplifies an effect or output. Negative feedback reduces what is being amplified, stabilizing the system.

Types of Feedback

There are two types of feedback: positive feedback and negative feedback.

Positive Feedback

Positive feedback is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in the magnitude of the perturbation.

Negative Feedback

Negative feedback occurs when some function of the output of a system, process, or mechanism is fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances.

Feedback in Biological Systems

Feedback is widely used in the regulation of biological systems. For example, the regulation of blood glucose provides an example of feedback in biological systems. In a negative feedback loop, increased output from the system inhibits future production by the system. In a positive feedback loop, increased output from the system promotes future production by the system.

Feedback in Engineering

In engineering, feedback is used to control systems and is helpful for stabilizing a system that could easily become unstable. It does this by continuously adjusting a system to keep it in a target state.

Feedback in Management

In management, feedback is a process in which the effect or output of an action is returned (fed back) to modify the next action. Feedback is essential to the workings of the feedback loop.

See Also

• Control theory
• Cybernetics
• Homeostasis

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