Stimulus Control and Prompt Fading

Types of Prompts

  • Prompting methods are broken down into:
    • Response prompts
    • Stimulus prompts

Response Prompts

  • Something added to the response assists the client in completing the response correctly.
  • Examples:
    • Physical prompts: Physically guiding the client to make the correct response.
    • Verbal instructions: Telling the client how to make the correct response.
    • Modeling: Demonstrating the correct response for the client.

Stimulus Prompts

  • Something added to the stimulus signals the response and assists the client in completing the response correctly.
  • Examples:
    • Positional prompts: Moving the target stimulus closer to the client.
    • Movement prompts: Tapping or pointing to indicate the correct response.
    • Redundancy: Exaggerating some dimension of the stimulus to cue the client to respond correctly.

Goals of Prompt Fading

  • To ensure the client can demonstrate the target response:
    • Independently
    • Accurately
    • In response to the correct stimulus (natural stimulus)

Stimulus Control

  • A response occurs more often in the presence of a particular stimulus than in its absence.
  • Stimuli gain control over responding because they become predictive of reinforcement.
  • Through effective prompt fading, stimulus control can be transferred from the prompt to the naturally occurring stimulus.
  • When using a prompt, the prompt initially evokes the correct response, followed by reinforcement, thus becoming predictive of reinforcement.
  • The natural stimulus and the prompting stimulus occur together, then the correct response is demonstrated, and reinforcement is provided.
  • Once the prompt is removed, the natural stimulus evokes the correct response and develops stimulus control.
  • Systematic prompt fading procedures are needed to successfully remove the prompt.

Prompt Fading Procedures for Response Prompts

  • Include:
    • Most to least prompting
    • Least to most prompting
    • Graduated guidance
    • Time delay
  • Correctly used, these procedures allow for transfer of stimulus control to the naturally occurring stimulus.

Most to Least Prompting

  • A prompt hierarchy is used.
  • The most intensive prompt is used immediately to ensure the client practices the correct response.
  • Less intensive prompts are used as the client demonstrates more independence.
  • Example hierarchy:
    • Maximum prompting (manual guidance)
    • Gesture
    • Model
    • No prompts (natural stimulus)
  • Shifting to different prompts occurs when the child performs a response with proficiency at a particular prompting level.

Least to Most Prompting

  • The opposite of most to least prompting.
  • The least intensive prompt is used first.
  • If the client cannot demonstrate the correct response, the next least intensive prompt is tried, and so on.
  • Example hierarchy:
    • No prompts (natural stimulus)
    • Model
    • Gesture
    • Physical prompt (manual guidance)
  • Moving along the hierarchy occurs only if the current prompting level does not produce the target response.

Graduated Guidance

  • Typically used when teaching behavior chains.
  • Physical prompts are provided at whatever level is necessary throughout the response.
  • The type of physical prompt may change throughout the response based on the client's level of independence.
  • Types of physical prompts:
    • Hand over hand
    • Wrist
    • Elbow
    • Shoulder

Time Delay

  • The interval between the presentation of the natural stimulus and the implementation of the prompt is varied.
  • Types:
    • Constant delay: The delay interval is set for a predetermined number of trials before being increased.
    • Progressive time delay: The delay interval is increased systematically based on the level of independence demonstrated by the client, rather than on a predetermined number of trials.