SPED 8013 | Chapter 13: Schedules of Reinforcement

Continuous Reinforcement (CRF)

  • Provides reinforcement for every occurrence of a behavior (not constantly for any behavior)
  • Sometimes abbreviated FR1
  • Advantageous for skill acquisition

Intermittent Schedules of Reinforcement (INT)

  • Used to strengthen established behaviors
  • Usually necessary or the progression to naturally occurring reinforcement

Basic Schedules of Reinforcement

  • Ratio (Instances)
    • Ratio schedules require a number of responses before one response produces reinforcement
    • At or around a fixed number of “instances” or “occurrences” of the correct target behavior
  • Interval (Time)
    • Interval schedules require an elapse of time before a response produces reinforcement
      • A specific amount of time elapses before a single response produces reinforcement
      • Reinforcement is contingent only on the occurrence of one response after the required time has elapsed
  • Fixed Schedules
    • Applicable to either ratio or interval application
    • With a fixed schedule, the response ratio or the time requirement remains constant
  • Variable Schedules
    • Applicable to either ration or interval application
    • The response or time requirement for reinforcement varies around an average

Fixed Ratio (FR)

  • Fixed Ratio 4 (FR 4) – Reinforcement is delivered after every 4th correct response
  • Fixed Ratio Schedule Effects
    • Consistency of performance
      • Produces a typical pattern of responding
        • After the first response of the ratio requirement, subject completes required responses with little hesitation
        • Post-reinforcement pause
    • Rate of Response
      • Often produce high rates of response
      • To a degree, the larger the ratio requirement, the higher the rate of response

Fixed Interval (FI)

  • Fixed Interval 2 min (FI 2) – Reinforcement is delivered for the response after the 2 minutes have elapsed
  • Provides reinforcement for the first correct response following a fixed duration of time
  • Elapse of time alone is not sufficient for reinforcer delivery
  • Fixed Interval Schedule Effects
    • Consistency of performance
      • Typically produce a post-reinforcement pause
      • Gradually accelerating rate of response towards the end of the interval is called an FI scallop
    • Rate of response
      • Tend to produce a slow to moderate rate of response
      • To a degree, the larger the fixed interval requirement, the longer the post-reinforcement pause

Variable Ratio (VR)

  • Variable Ratio – (VR 4). An average of every 4th correct occurrence
  • Variable Ratio Schedule Effects
    • Consistency of Performance
      • Produce consistent, steady rates of response
      • Do not produce a post-reinforcement pause

Variable Interval (VI)

  • Variable Interval 2 minute (VI 2). Reinforcing the first occurrence after an average elapsed time of 2 minutes
  • Provides reinforcement for the first correct response following the elapse of variable durations of time
  • “Average” amount of time
  • Variable Interval Schedule Effects
    • Consistency of performance
      • Tends to produce a constant, stable rate of response
      • Typically produces few hesitations between responses
    • Rate of Response
      • Tends to produce low to moderate rate of response
      • The larger the average interval, the lower the overall rate of response

Limited Hold

  • In an interval schedule, reinforcement remains available for a finite time following the elapse of the interval.
  • If the response does not occur, the opportunity for reinforcement is missed

Thinning Intermittent Reinforcement

  • One of two methods commonly used:
    • Gradually increasing the response ration or the duration of the time interval
    • Providing instructions such as rules, directions and signs to communicate the schedule of reinforcement
  • Ratio Strain
    • A result of abrupt increases in ratio requirements
    • Characteristics include: avoidance, aggression, and unpredictable pauses in responding

Variations on Basic Intermittent Schedules of Reinforcement

  • Schedules of Differential Reinforcement of Rates of Responding
    • Provides an intervention for behavior problems associated with rate of response
      • Variation of ratio schedules
    • Differential reinforcement of high rates (DRH)
      • Reinforcement of responses higher than a predetermined criterion
    • Differential reinforcement of low rates (DRL)
      • Responses are reinforced only when they are lower than the criterion
    • Spaced-responding DRH or HRL
      • Reinforcement is available for responses that are separated by a given duration
      • Used almost exclusively in the laboratory
    • Full Session DRH
      • Provides reinforcement if the total number of responses during the session meets or exceeds a number criterion
    • Full Session DRL
      • Provides reinforcement if the total number of responses during the session is at or below a number criterion

Compound Schedules (Don’t get to hung up on this in the Cooper text)

  • Often there are multiple contingencies of reinforcement in place at any one time
    • Especially in the applied setting
  • Behavior will often reflect these various reinforcement schedules–planned or unplanned

Compound Schedules of Reinforcement

  • The Matching Law
    • Rate of responding typically is proportional to the rate of reinforcement received from each choice alternative
    • Concurrent Performances: Formalizing the Matching Law
      • Concurrent interval schedules: participants typically do not allocate all of their responses exclusively to the richer schedule
      • Concurrent ratio schedules: participants are sensitive to the ratio schedules and tend to maximize reinforcement by responding primarily to the ratio that produces the higher rate of reinforcement

Perspectives on Schedule Effects in Applied Settings

  • Most applied applications only approximate true laboratory schedules
  • Many uncontrolled variables in applied settings will influence a participant’s sensitivity to the schedule