Elements of operant conditioning: schedules of reinforcement
- The way reinforcement is delivered
- A schedule of reinforcement is a program for giving reinforcement; specifically the frequency and manner in which a desired response is reinforced
- The schedule that is used will influence the speed of learning and the strength of the learned response
- Early in conditioning process,, learning = most rapid if desired response is reinforced every time
• Reinforcer = typically provided immediately after every correct response
- This schedule of reinforcement is called continuous schedule
- …
- Skinner (1956) unintentionally observed this property of reinforcement when he ran out of food pellets for his rats during the experiment –> had to deliver reinforcement less often
• Responses maintained through a program of partial reinforcement = stronger and less likely to weaken or cease that those maintained by continuous reinforcement
• Partial reinforcement is the process of reinforcing some correct responses but not all of them.
• May be delivered in a number of ways or by using different schedules
• Can be given after a certain number, time or on a regular/unpredictable basis
Fixed- ration schedule
- Is when reinforcer is given after a set (fixed) unvarying number (ratio) of desired responses have been made
- However ratio needs to e relatively frequent one in the acquisition phase of the learning process. After = frequency can be extended
Variable ration schedule
- When the reinforcer is given after an unpredictable (variable) number (ratio) of correct responses
- There is also a constant mean number of correct responses (a ratio) for giving reinforcement
- Schedule might reinforce, on average, ten correct responses in a total of 100 correct responses  but sometimes after one, five, 13 – as long as average of 10 is maintained
- Uncertainty about when the next reinforcement will occur keeps organism responding steadily and extinction takes longer
- E.g. gambling  random ratio reinforcement schedule
Fixed-time schedule
- Involves the delivery of the reinforcer after a specific, or fixed, time has elapsed since the previous reinforcer, provided the correct response has been made
- E.g. first correct response after 30 seconds is reinforced
- In the lab = generally produces a moderate response rate that is often erratic. When organism realises that time is the key factor, it stops responding for a while but quickly
Variable interval schedule
- Is when reinforcement is given after irregular, or ‘variable’ periods (intervals have passed, provided the correct responses has been made
- There is a mean period of time (like the variable ration schedule and responses made before the scheduled delivery time are not reinforced, even if the responses are correct
- Since reinforcement cannot be predicted  produces a low but very steady rate of responding. Weakening or cessation = gradual and much slower than under a fixed interval schedule
- E.g. surprise tests by a teacher or portable speed cameras on