feedback loop
in cybernetic theory, a self-regulatory model that determines whether the current operation of a system is acceptable and, if not, attempts to make the necessary changes. Its operation is summarized by the acronym TOTE (test-operate-test-exit). The two test phases compare the current reality against the goal or standard. The operate phase involves any processes or interventions designed to resolve unacceptable discrepancies between the reality and the standard. In the exit phase, the supervisory feedback loop is closed down because the circumstances have been brought into agreement with the standard. Also called TOTE model. See also negative feedback.