Schedules of Reinforcement
Reinforcement – any stimulus that makes a behavior more likely to occur. In terms of
delivering reinforcement one may:
1. Vary the frequency of the reward strictly according to time intervals. These
are called interval schedules – the number of responses which occur, after the
first correct response in an interval, are irrelevant.
2. Vary the frequency of the reward according to the rate of response. These are
called ratio schedules – time is irrelevant.
Within these 2 types of schedules a reward is given on either:
A. A regular basis, called a fixed schedule or
B. On an intermittent (random / pattern less) manner called a variable schedule;
the reward according to the rate of response. These are called ratio schedules – time is
irrelevant.
Combine these to define the schedules listed below:
1) Fixed-interval schedule
2) Variable-interval schedule
3) Fixed-ratio schedule
4) Variable-ration schedule
To determine the schedule of reinforcement being used, ask yourself: Is time the major
factor that causes a favorable outcome (reinforcement) or is it repetition of responses?
If time or the needed repetition of responses is constant or patterned, it is fixed; if the
time or repetition of responses is random or intermittent, it is variable.
Write fixed interval (FI), fixed-ratio (FR), variable interval (VI), or variable ratio (VR) for
each example.
-------------------------------------------------------------------------------------------------Ask yourself:
 Who is being rewarded?
 What is the reward?
 Remember you are defining reinforcement not punishment.
(Suggestion added by Martin Anderson)
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15
Answer
Paid 10 dollars for every 20 puzzles solved
Studying for a class that has surprise quizzes
Slot machines are based on this schedule
Trolling for fish in a lake in the summer
Speed traps on highways
Selling a product door to door
Getting the clothes out of the dryer once it buzzes
Going up a staircase to reach a landing with a nice view
Doing 20 pushups to help stay fit
Playing Bingo
Getting a paycheck at the end of 2 weeks
Random drug testing
A strike in bowling
Calling your mechanic to see if your car is fixed yet
Frequent flyer program where one gets a free flight after a specific number
of miles flown
16 Child screams and cries in store to get what he wants, every so often it
works
17 Child who likes to hear theme music from Jeopardy every night at 7PM
18 Trying to find a parking spot in Metropolis with a meter that works
19 Wife is watching boxing match with husband – she receives a kiss at the of
every 3-minute round
20 Waiting for a sunny day to go the beach
21 Surfer waiting for the perfect wave to ride in on
22 Looking under rocks for worms
-------------------------------------------------------------------------------------------------Answer Key
1
FR
5
VI
9
FR
13 VR
17 FI
21 VI
2
VI
6
VR
10 VR
14 VI
18 VR
22 VR
3
VR
7
FI
11 FI
15 FR
19 FI
4
VI
8
FR
12 VI
16 VR
20 VI
The above activity was originally published in the March /April 1995 issue of The Psychology Teacher Network.
The activity is reprinted here with the permission of the Education Directorate of the APA. Further
publication of the activity is not permitted without the express written consent of the Education Directorate.