A schedule of reinforcement defines when reinforcement is to be give. They can be based on time (an interval schedule) or on a number of occurrences of the behavior (a ratio schedule).

The conditions under which reinforcement is delivered.

The pattern of occasions on which responses are to be reinforced. Commonly, reinforcement is scheduled after a stipulated number of responses occurs or when a response occurs after a preset time interval has elpased. See also ratio schedule, interval schedules.