Schedules of Reinforcement
n  Continuous
vs. Intermittent Schedules
n Ratio
vs. Interval Schedules
n Fixed
vs. Variable Schedules
n  Response
Patterns and Rates
Continuous vs. Intermittent Schedules
n
Schedule of Reinforcement: Rules according to
which the behavioral response (R) is reinforced
n
Continuous (CRF) = every response is reinforced
n
Intermittent schedules are far more common
Intermittent Schedules cont.
n
Ratio Schedules: reinforcement SR depends on the
number of times a response R is repeated, or the
amount of behavior that is emitted.
n  More responses (Rs) = more reinforcers (SRs)
n
Interval Schedules: reinforcement SR depends upon
the passage of time, plus one response.
n  Responses during the interval are NOT reinforced!
Subject must wait until enough time has passed,
and then make one response to get SR
Intermittent Schedules cont.
Ratio or Interval – which one?
Can I get SR faster if I emit more responses?
n  Can I get more SRs if I work harder?
n  Yes = Ratio
n
n
Do I have to wait a certain amount of time?
n  Yes = Interval
Intermittent Schedules cont.
Fixed vs. Variable schedules
n
Fixed schedule: SR is predictable
Ratio (FR) = get SR after every X responses
n  Fixed Interval (FI) = get SR after every X seconds, plus
one response
n  Fixed
n
Variable schedule: SR is unpredictable
Ratio (VR) = get SR after about every X
responses
n  Variable Interval (VI) = get SR after about every X
seconds, plus one response
n  Variable
Response Patterns and Rates
n
Pattern of Responses: how responses are distributed
between reinforcers
n
Rate of Responses: number of responses per minute
Response Patterns and Rates cont.
n
FR: Rate is high until SR, then pause
Pattern resembles steps
n
FI: Rate starts low, increases closer to SR, with postreinforcement pause
Pattern resembles shallow scallops
n
VR: Rate is extremely high and steady with NO pauses
Pattern is a steep slope
n
VI: Rate is steady with no pauses, not as high as VR
Pattern is a moderate slope
Schedules of reinforcement
Fixed ratio- buy 5 get 1
free cards
n  Variable ratio- slot
machines
n
Fixed interval- paycheck;
study for exam
n  Variable interval- study for
pop quiz
n
Superstition (Skinner, 1948)
n
What occurs when a reinforcer (SR) is NOT contingent
n
S connects unnecessary Bs with non-contingent SR
n  Humans’
n  We
behavior will change over time
do learn, even under non-contingent reinforcement
Superstitious Behaviors
Non-contingent reinforcement
(coincidental rewards)
Operant: Pigeons movie
Reading? Free will?