Social, philosophical, and economic pressures are confronting curriculum designers with the major problem of designing instruction which produces consistently high learning despite wide variation in student characteristics. This is essentially a cybernetic question of regulating variety in a system to produce a stable output. It is observed that biological, contrived, and social systems all maintain a steady state by means of such devices as recognition of desired output, attenuation of input variety, sensing and signalling functions, and intervention mechanisms. Parallels to instruction suggest five basic propositions which relate to the design of instruction capable of producing consistently high learning output. (Author)