Schedules of Reinforcement Chapter 13

1
Mean 13.25 83
14.75
12
14.5
12
13
13.75
12.5
13.5
12.75
13
14
2
Schedules of ReinforcementChapter 13
3
Whats a Schedule?

• A schedule of reinforcement is a rule specifying
• the arrangement and response requirements for
  reinforcement
• e.g., whether a reinforcer follows every
  behavior, every other behavior, etc.
• 2 Simple Schedules
• Continuous Reinforcement (CRF FR1)
• The reinforcer follows every behavior
• CRF results in rapid acquisition (good for
  teaching)
• CRF produces little resistance to extinction
• Extinction (EXT)
• Discontinuation of a response-reinforcer
  contingency

4
Intermittent Reinforcement

• Some rather than all responses are reinforced
• Two main categories
• Ratio schedules the reinforcer is delivered
  after every X behaviors
• Interval schedules the FIRST behavior after X
  amount of time is reinforced
• Produces better resistance to extinction than CRF
• Good for maintaining behavior

5
Ratio Schedules

• 2 Types Fixed Ratio and Variable Ratio
• Fixed Ratio the reinforcer is delivered after a
  fixed number of behaviors
• Designation FR 5 (every 5th target response is
  reinforced)
• Produces high-rate responding why?
• Produces a post-reinforcement pause (PRP)
• PRPs are proportional to the size of the ratio
• e.g., piecework

6
Fixed-Ratio Schedule of Reinforcement
PRP
SR delivered
7
Variable Ratio

• The reinforcer is delivered after an average
  number of behaviors
• Designation VR 5
• 5, 4, 7, 6, 4, 3, 6, 7, 3
• Produces consistent, high rates with no PRPs
• e.g., starting a lawn mower
• Clinical applications

8
Tic-Tac-Toe VR Procedure
27 5 23
11 15 9
3 20 10

• Teacher picks maximum number of responses for an
  individual or group (e.g., 30)
• The smaller the , the more likely it is that the
  learner(s) will meet the contingency
• Learners fill in each square of tic-tac-toe grid
  with a no greater than the max
• Teacher fills box with numbers on slips of paper
• Each number several times
• Contingent on target behavior, student picks slip
  of paper
• If on tic-tac-toe, cross out number
• Deliver SR when 3 in a row

5
9
Classroom Lottery VR Procedure

• Students write their names on index cards after
  successfully completing assigned tasks
• Cards go in a box
• After a preset period of time (e.g., 1 week),
• Teacher picks a card that student is the winner
• The more cards earned, the more likely a student
  will be the winner

Reggie
Lottery Box!
10
Considerations with Ratio Schedules

• Both FR and VR schedules have 2 major advantages
• Produce high rates of responding
• Easy to use
• Potential Disadvantage
• Ratio strain can result from abrupt increases in
  ratio requirements

11
Interval Schedules

• 2 Types Fixed Interval and Variable Interval
• Fixed Interval the reinforcer is delivered for
  the first target response after a fixed period of
  time has elapsed
• Designation FI 60s
• e.g., turning on the TV to watch your favorite
  show
• Characteristics
• Produces PRPs, resulting in scallop or
  break-and-run patterns
• Slow to moderate rate of responding

12
PRP
SR delivered
13
Variable Interval Schedule

• the reinforcer is delivered for the first
  behavior after an average period of time has
  elapsed
• Designation VI 60s
• produces steady, moderate responding (no PRPs)
• e.g., checking e-mail
• Limited Hold a feature that can be added to any
  interval schedule
• The behavior must occur after the interval has
  elapsed, but within a specific period of time
• Designation FI 5 min LH 30 s

14
(No Transcript)
15
Considerations with Interval Schedules

• Use if you want to produce low to moderate
  response rates
• Advantage
• FI schedules are relatively easy to use with a
  resetting timer
• Potential Disadvantage
• Off-task or other unwanted behavior may occur
  during the PRP

16
responses
FI scallop
Post-reinforcement pause
time
17
Thinning the Schedule of Reinforcement

• Schedule thinning Gradually increasing the
  response ratio or the extent of the time interval
  
• Benefits
• The students behavior becomes more durable (more
  resistant to extinction)
• More practical for caregivers to implement
• If you move too quickly, you can produce ratio
  strain
• Aggression
• Extinction of responding
• Not many guidelines are available to tell us how
  to do this

18
LeBlanc, Hagopian, Maglieri, Poling (2002)

• Determine a reasonable terminal goal thats
  appropriate to the age and functioning level of
  the learner
• Establish a series of steps between the initial
  value and the terminal value
• 8-12 steps are recommended
• Increase 33 to 50 at each step
• Stay at one step at least 2 times
• If student is unsuccessful, go back a step
• Periodically probe a few steps ahead

19
LeBlanc et al. Thinning from FR1
1 FR2 100
2 FR4 100
3 FR6 50
4 FR9 50
5 FR12 33
6 FR16 33
7 FR21 33
8 FR28 33
20
Differential Reinforcement of Rates of Responding

• DRH Reinforcement of responses higher than a
  predetermined criterion (to produce a higher rate
  of responding)
• DRL Reinforcement of responses lower than a
  predetermined criterion (to produce a lower rate
  of responding)
• 3 Types
• Spaced-responding reinforcement is only
  available for responses separated by a given
  duration of time (IRT)
• Not used much b/c its difficult to calculate IRT
• Full session reinforcement is delivered at the
  end of the session if the total number of
  responses during the session was less than or
  more than a criterion
• Interval Total session is divided into equal
  intervals and reinforcement is delivered at the
  end of each interval in which the number of
  responses was less than or more than a criterion

21
Compound Schedules of Reinforcement

• Combine different types of schedules
• Concurrent Schedules
• Discriminative Schedules
• Multiple Schedules
• Chained Schedules
• Nondiscriminative Schedules
• Mixed Schedules
• Tandem Schedules

22
Concurrent Schedules

• 2 or more contingencies of reinforcement operate
  independently and at the same time for 2 or more
  behaviors
• Used for
• Reinforcer Assessments
• Intervention Assessments
• Hanley et al. (2005) allowed individuals to
  choose which intervention they preferred
• FCT Punishment was preferred to FCT
  Extinction
• Interventions
• Hoch et al. (2002) boys with autism could play
  alone or with sibling
• Sibling was chosen when SR magnitude and quality
  were increased
• Use this when you cant or shouldnt treat
  inappropriate behavior directly

23
Multiple Schedule

• A type of discriminative schedule
• Two or more schedules are presented one after
  another
• Each is correlated with a discriminative stimulus
• Tiger and Hanley (2004)
• Different colored leis worn by the teacher were
  SDs correlated with schedules of reinforcement
  for attention

24
(No Transcript)
25
FR1 Component (SD)
26
EXT Component (S?)
27
15 s 270 s
5s1s
1 s 60 s
Minimum response criterion
28
Chained Schedule

• A type of discriminative schedule
• Differs from multiple schedule
• Schedules in the chain occur in the same order
• Behavior may be the same or different for each
  component of the chain
• Conditioned reinforcement for the first element
  of the chain is presentation of the second
  element
• The last response is reinforced with most
  powerful reinforcer

29
Nondiscriminative Schedules

• Mixed (like multiple schedule without the SDs)
• Tiger and Hanley (2004) conducted the same
  sessions without the teacher wearing leis
• Tandem (like chained with out the SDs)

30
Use Caution

• When extrapolating information about schedules
  from basic research to applied settings
• Most applications of schedules only approximate
  lab schedules
• Many uncontrolled variables in applied settings
  will influence a persons sensitivity and
  insensitivity to a schedule of reinforcement