in the psychology of conditioning, established procedures or sequences for reinforcing operant behavior; e.g., in a lever-pressing situation, every displacement of the lever will bring a pellet of food or comparable reinforcer (continuous reinforcement schedule), or the reinforcer will come at every 5 seconds, regardless of how many displacements occur earlier (fixed-interval reinforcement schedule), at every tenth displacement (fixed-ratio reinforcement schedule), or on an average of every 5 seconds (variable-interval reinforcement schedule), or the reinforcer will come in a noncontinuous fashion in which less than 100% of the displacements bring a reinforcer (intermittent reinforcement schedule).