SPED 8013 | Chapter 20: Chaining

Definition of a Behavior Chain

  • A specific sequence of discrete responses
  • Each associated with a particular stimulus condition
  • When individual components are linked together, they form a chain that produces a terminal outcome

Components in a Chain Serve Dual Functions

  • Each response in the chain produces a stimulus change that serves as a conditioned reinforcer for the response that produced it
  • And as a discriminative stimulus for the next response in the chain
  • (Exceptions: The first and last responses in the chain)

Behavior Chain with a Limited Hold

  • A sequence of behaviors that must be performed accurately and within a specified time to produce reinforcement
  • Emphasizes both accuracy and proficiency

Characteristics of Behavior Chains

  • A series of discrete responses
  • Performance of behavior changes the environment such that it produces conditioned reinforcement for previous response and serves as Sfor next response
  • Behaviors must occur in sequence and in close temporal succession

 Rationale for Chaining

  • Teaches complex skills that allow individuals to function more independently
  • Provides the means by which a series of discrete behaviors can be combined to occasion reinforcement – a way to add new behaviors to an existing behavioral repertoire
  • Can easily be combined with other procedures (prompting, instructions, reinforcement)

 Task Analysis

  • Breaking a complex skill into smaller, teachable units, the product of which is a series of sequentially ordered steps

Constructing a Task Analysis

  • Notes:
    • The sequence one individual may  use to perform skill may not be the same as another individual
    • Must be individualized according to
      • Age
      • Skill level
      • Prior experience
      • “Sensibilities”
    • Some task analyses have a limited number of steps, but these steps may be broken down into subtasks
  • Methods
    • Observe a competent individual perform the task
    • Consult with experts or persons skilled in performing the task
    • Perform the task oneself
      • Can refine it as you use it, if necessary

Assessing Mastery Level

  • Single-Opportunity Method
    • Give cue to begin task
    • Record learner performance with a + or a – for each step
    • Assessment stops as soon as a step is performed incorrectly
    • Remaining steps are scored with a –
  • Multiple-Opportunity Method
    • Give cue to begin task
    • Record learner performance with a + or a – for each step
    • If a step is performed incorrectly, the trainer completes that step for the learner and positions them for the next step
    • Learner continues to the next step
    • Do NOT co-mingle teaching with assessment

Single vs. Multiple Method?

  • Single-Opportunity method
    • More conservative
    • Gives less information
    • Quicker to conduct
    • Reduces likelihood of learning taking place during assessment
  • Multiple-Opportunity method
    • Takes more time to complete
    • Provides trainer with more information
    • May make training more efficient by allowing trainer to eliminate instruction on already-learned steps

 Behavior Chaining Procedures

  • Forward Chaining
    • The behaviors identified in the task analysis are taught in their naturally occurring order
    • Reinforcement is delivered when the predetermined criterion for the first behavior in the sequence is achieved
    • Training only occurs on the steps previously mastered and the current step (no training on steps after that)
      • Advantages:
        • Can be used to link smaller chains to larger ones
        • Relatively easy
  • Total-Task Chaining
    • A variation of forward chaining
    • Training is provided for every behavior in the sequence during every training session
    • Trainer assistance (prompting) is provided with any step the person is unable to perform independently
    • Continue training until the learner is able to perform all behaviors to criterion
  • Backward Chaining
    • All the behaviors identified in the task analysis are initially completed by the trainer, except for the final behavior in the chain
    • Once the final behavior is mastered, reinforcement is delivered for the last two in the chain, etc.
      • Advantages:
        • Natural reinforcement is produced immediately upon the learner’s response
        • Learner contacts these natural contingencies of reinforcement on every learning trial
  • Backward Chaining with Leap Aheads
    • Follows same procedures as backward chaining, but not every step in the task analysis is trained
    • Other steps are probed
    • If some steps are in the learner’s repertoire, they are not taught
    • The learner is still required to perform those steps, however

 Which Procedure to Use?

  • No data to indicate one is more effective than another
  • Choose total-task chaining if
    • Learner knows many of the tasks but needs to learn how to do them in sequence
    • Has an imitative repertoire
    • Has moderate to severe disabilities
    • Task is not long or complex
  • Uncertainty may be minimized by personalization

Behavior Chain Interruption Strategy (BCIS)

  • Chain is interrupted at a predetermined step so that another behavior can be emitted
  • Interruption may cause some distress
    • It momentarily blocks access to reinforcement
  • This is somewhat desirable because it creates motivation to learn the new behavior in the chain
    •  As long as it is not so distressful that it causes emotional responding or self-injurious behavior
  • Collect Baseline Data
  • Direct person to start chain
  • At predetermined point, restrict learner’s ability to complete next step
  • Prompt learner to engage in new targeted step
  • Then allow the individual to proceed with the chain

Breaking Inappropriate Chains

  • Determine initial Sand substitute an Sfor an alternative behavior, or
  • Extend chain and build in time delays
  • Examine potential sources of difficulty in the chain
    • Re-examine SDs and responses
      • Is sequence arbitrary? Would rearranging sequence help?
    • Determine whether similar SDs cue different responses
      • If so, can the sequence be rearranged to separate the two similar SDs?
    • Analyze the job setting to identify relevant and irrelevant SDs
      • Do you need to implement discrimination training so that the learner can discriminate the relevant from irrelevant SDs?
    • Determine whether SDs in the job setting differ from training SDs
      • May need to conduct some training in job setting
    • Identify presence of novel stimuli in the environment
      • Discrimination training might be necessary to teach the learner to ignore novel, irrelevant stimuli

Factors Affecting Performance

  • Completeness of the task analysis
    • More complete, detailed task analyses tend to produce better learning
      • Time developing task analyses is well spent
      • Be ready/willing to modify it after it is constructed
  • Length/Complexity of chain
    • Longer chains take more time to learn
  • Schedule of Reinforcement
    • Must use appropriate schedule (Ch. 13)
    • Consider number of responses in chain when determining the schedule
  • Extinction
    • Responses performed further from the reinforcer may become less likely
    • This interrupts the Srelation and can result in withering performance of the chain
    • Lesson: adjust reinforcement schedule accordingly (use intermittent schedules)
  • Stimulus Variation
    • Introduce all variations of the stimulus items to be encountered later to increase generalization of the chain
  • Response Variation
    • Varied responses may be needed to deal with stimulus variation
    • This may require some retraining of responses