a schedule or reinforcement is a pattern of delivering partial reinforcement in operant conditioning trials, where the frequency of the delivery changes according to the type of pattern.
In Skinner's experiments, food was delivered every the rat pressed the lever. This is known as continuous reinforcement.
Continuous reinforcement: reinforcement that follows every response it is intended to strengthen.
Skinner also conducted experiments in which only some responses were reinforced, a process known as partial reinforcement.
Partial reinforcement: reinforcement that follows only some of the responses it is intended to strengthen.
Skinner varied how often reinforcement occurred in order to see the impact this would have on how quickly the learning would take place, and how long the behaviour would continue once learned. These findings are important as it may not be possible or desirable to reinforce every single response, such as when teaching a dog to sit. Skinner identified four different variations of providing partial reinforcement, known as schedules of reinforcement.