Transcript Schedules of Reinforcement

Chapter 7
Operant Conditioning:
Schedules and Theories
Of Reinforcement
Now that we have discussed
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 Liv-a-Snap 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. Intermittent
Reinforcement
Continuous

A continuous
reinforcement
schedule (CRF) is
one in which each
specified response is
reinforced
Intermittent

An intermittent
reinforcement
schedule is one in
which only some
responses are
reinforced
Intermittent 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 Intermittent
Schedules
Ratio Schedules
Interval Schedules

Fixed Ratio

Fixed Interval

Variable Ratio

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, continued
Higher Ratio requirements result in
longer post-reinforcement pauses

Example: The longer the chapter you read,
the longer the study break!
Ratio Strain – a disruption in responding
due to an overly demanding response
requirement

Movement from “dense/rich” to “lean”
schedule should be done gradually
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
Other facts about
Variable Ratio Schedules

Behaviors on this type of schedule tend to
be very persistent
This includes unwanted behaviors like begging,
gambling, and being in abusive relationships
 “Stretching the ratio” means starting out with a
very dense, rich reinforcement schedule and
gradually decreasing the amount of
reinforcement


The spouse, gambler, or child who is the “victim”
must work harder and harder to get the reinforcer
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

Characteristic pattern:



A “scallop” pattern produced by a post-reinforcement
pause followed by a gradually increasing rate of
response as the time interval draws to a close
Glancing at your watch during class provides an
example!
Student study behavior provides another!
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 postreinforcement 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
Noncontingent Reinforcement
What happens when reinforcement
occurs randomly, regardless of a person
or animal’s behavior?
Weird Stuff!

Like what?
Superstitious Behavior
Examples include:
Rituals of gamblers, baseball players, etc.
 Elevator-button-pushing behavior

Noncontingent reinforcement can
sometimes be used for GOOD purposes
(not just weird or useless behaviors!)
Good, useful examples
Giving noncontingent attention to
children
Some bad behaviors like tantrums are
used to try to get attention from caregivers
 These behaviors can be diminished by
giving attention noncontingently

Children need both contingent AND noncontingent attention to grown up healthy
and happy!
Theories of Reinforcement
In the effort to answer the question,
“What makes reinforcers work?”,
theorists have developed some . . . . .
THEORIES!!!!!
So here’s the first one:
If you are hungry and go looking for
food and eat some, you will feel more
comfortable because the hunger has
been reduced.
The desire to have the uncomfortable
“hunger drive” reduced motivates you to
seek out and eat the food
Drive Reduction Theory
So this is one thing that can make
reinforcers work:
An event is reinforcing to the extent that it
is associated with a reduction in some type
of physiological drive
 This type of approach may explain some
behaviors (like sex) but not others (like
playing video games)

Incentive Motivation
Sometimes, we just do things because
they are FUN!
When this happens, we can say that
motivation is coming from some
property of the reinforcer itself rather
than from some kind of internal drive

Examples include playing games and
sports, putting spices on food, etc.
We can also think about how
we use reinforcers.
We can use a behavior we love (high
probability behavior) to reinforce a behavior
we don’t like to do very much (low probability
behavior).


This is sometimes called “Grandma’s Principle”
Bobby, you can read those comic books once you
have mowed the grass!
To use this theory, you have to know the
“relative probability” of each behavior
What do you do if you only
know the “probability” for one?
You can use the next theory!
Let’s say you know that a person likes
to play video games. You can use
playing video games as a reinforcer IF
you:
Restrict access to playing
 Make sure the person is getting to play
less frequently than they prefer to

This is the “Response
Deprivation Hypothesis”
Any behavior that you can restrict
access to and keep it below the person
or animal’s preferred level of doing it
can be used as a reinforcer
Think of some examples!
Behavioral Bliss Point
The Response Deprivation Hypothesis
makes an assumption that there is an
optimal or best level of behavior that a
person or animal tries to maintain
If you could do ANYTHING at all you
wanted to do, how would you distribute
your time?
 This would tell you your “behavioral bliss
point” for each activity or behavior

Behavioral Bliss Point cont’d
An organism that has free access to
alternative activities will distribute its
behavior in such a way as to maximize
overall reinforcement
In other words, if you can do anything
you want, you will spend time on each
thing you do in a way that will give you
the most pleasure
But this is real life!
This means that you can almost never
achieve your “behavioral bliss point”
So you have to compromise by coming
as close as you can, given your
circumstances
No wonder we hate to leave our
childhoods behind!