Operant Conditioning:

Schedules and Theories

Of Reinforcement

Now that we have discussed punishment and reinforcement. . .

It is time to discuss just HOW reinforcements can and should be delivered

In other words, there are other things to consider than just WHAT the reinforcer should be!

Think about this!

If you were going to reinforce your puppy for going to the bathroom outside, how would you do it?Would you give him a Milk Bone every

time? Some of the time? Would you keep doing it the same way or

would you change your method as you go along?

What is a schedule of reinforcement?

A schedule of reinforcement is the response requirement that must be met in order to obtain reinforcement. In other words, it is what you have to do to

get the goodies!

Continuous vs. Partial Reinforcement

Continuous A continuous

reinforcement schedule is one in which each specified response is reinforced

Partial A partial

reinforcement schedule is one in which only some responses are reinforced

Partial Reinforcement Schedules

When you want to reinforce based on a certain number of responses occurring (for example, doing a certain number of math problems correctly), you can use a ratio schedule

When you want to reinforce the first response after a certain amount of time has passed (for example when a teacher gives a midterm test), you can use an interval schedule

Four Types of Partial Schedules

Ratio Schedules

Fixed Ratio

Variable Ratio

Interval Schedules

Fixed Interval

Variable Interval

Fixed Ratio Schedule

On a fixed ratio schedule, reinforcement is contingent upon a fixed, predictable number of responses Characteristic pattern:

High rate of response Short pause following each reinforcer

Reading a chapter then taking a break is an example

A good strategy for “getting started” is to start with an easy task

Fixed Ratio: FR

Fixed Ratio is abbreviated “FR” and a number showing how many responses must be made to get the reinforcer is added:Ex. FR 5 (5 responses needed to get a

reinforcer)

Variable Ratio Schedule

On a variable ratio schedule, reinforcement is contingent upon a varying, unpredictable number of responses Characteristic pattern:

High and steady rate of response Little or no post-reinforcer pausing

Hunting, fishing, golfing, shooting hoops, and telemarketing are examples of behaviors on this type of schedule

Variable Ratio: VR

Variable Ratio: VR

Variable Ratio is abbreviated “VR” and a number showing an average of how many responses between 1 and 100 must be made to get the reinforcer is added: Ex. VR 50 (an average of 50 responses needed to

get a reinforcer – could the the next try, or it could take 72!

Gambling is the classic example!

Fixed Interval Schedules

On a fixed interval schedule, reinforcement is contingent upon the first response after a fixed, predictable period of time Glancing at your watch during class provides an

example! The mailman delivering your mail at a specific time

every day.

Fixed Interval: FI

Fixed Interval is abbreviated “FI” and a number showing how much time must pass before the reinforcer is available:FI 30-min (reinforcement is available for

the first response after 30 minutes have passed)

Ex. Looking down the tracks for the train if it comes every 30 minutes

Variable Interval Schedule

On a variable interval schedule, reinforcement is contingent upon the first response after a varying, unpredictable period of time Characteristic pattern:

A moderate, steady rate of response with little or no post-reinforcement pause.

Looking down the street for the bus if you are waiting and have no idea how often it comes provides an example!

Variable Interval: VI

Variable Interval is abbreviated “VI” and a number showing the average time interval that must pass before the reinforcer is available: VI 30-min (reinforcement is available for the first

response after an average of 30 minutes has passed)

Ex. Hilary’s boyfriend, Michael, gets out of school and turns on his phone some time between 3:00 and 3:30 – the “reward” of his answering his phone puts her calling behavior on a VI schedule, so she calls every few minutes until he answers