# Good Regulator Theorem **Domain:** Cybernetics / Control Theory **Doc Type:** Theorem **Maturity:** Developed **Related:** [[Roger Conant]], [[W. Ross Ashby]], [[Requisite Variety]], [[Control Systems]], [[Schedule and Loop]] ## Definition The Good Regulator Theorem, formulated by Roger Conant and W. Ross Ashby, states in its canonical form that every good regulator of a system must be a model of that system. ## Schedule–Loop Context It is the loop-side counterpoint to behaviorism. Effective regulation of a complex system depends on internal modeling, unless the regulator first suppresses the variety it cannot model. ## Backlinks - [[Schedule and Loop]] - [[articles/Schedule and Loop|Schedule and Loop]] - [[Russia and Prussia Kybernetiks]]