Chapters 56 Richards text Chapter 8 first half Cooper text Reversal aka Withdrawal Designs in Single

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Chapters 5-6 (Richards text)Chapter 8 (first
half) (Cooper text) Reversal (a/k/a Withdrawal)
Designs in Single-Subject Research

• Ps534
• Dr. Ken Reeve
• Caldwell College
• Graduate Programs in ABA

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Single-Case Experimental Designs

• Traditionally called single-subject designs
• Now referred to as single-case and
  single-participant designs
• Historical tradition Behavior Analysis
• Techniques and logic applied to other research
  areas
• If done well, is a perfectly valid research
  design

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Single-Case Experimental Designs Terminology

• AB baseline ? intervention
• ABA baseline ? intervention ? baseline
• ABAB baseline ? intervention ? baseline ?
  intervention
• BAB intervention ? baseline ? intervention

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Single-Case Experimental Designs Issues

• For each design we will ask the following
• Does the design allow us to see a change in DV
  (without regard to whether it was caused by the
  IV)?
• Does the design allow us to infer a functional
  relationship between IV and DV? Why does it
  allows this?
• What threats to internal validity (confounds)
  does the design control for?
• What ethical issues are important to know about
  using a particular design?

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Single-Case Experimental Designs The AB design
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Single-Case Experimental Designs The AB design

• Does the design allow us to see a change in DV
  (without regard to whether it was caused by the
  IV)? YES
• Does the design allow us to infer a functional
  relationship between IV and DV? NO. Why DOESNT
  it allows this?
• What threats to internal validity (confounds)
  does the design control for? NONE
• Ethical issues?

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The ABA Withdrawal (Reversal)
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The ABA Withdrawal (Reversal)

• Does the design allow us to see a change in DV
  (without regard to whether it was caused by the
  IV)? YES
• Does the design allow us to infer a functional
  relationship between IV and DV? YES.
• Why DOES it allows this? IF ONLY IV IS
  MANIPULATED, THEN NOT LIKELY ANYTHING BUT IV
  CAUSED CHANGES IN DV
• What threats to internal validity (confounds)
  does the design control for? MATURATION HISTORY
• Ethical issues? BETTER BECAUSE IT ENDS ON
  TREATMENT

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The ABAB Withdrawal (Repeated Reversal)
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The ABAB Withdrawal (Repeated Reversal)

• Does the design allow us to see a change in DV
  (without regard to whether it was caused by the
  IV)? DUH
• Does the design allow us to infer a functional
  relationship between IV and DV? YES, EVEN BETTER
  THAN THE ABA DESIGN.
• Why DOES it allows this? IF ONLY IV IS
  MANIPULATED, THEN NOT LIKELY ANYTHING BUT IV
  CAUSED CHANGES IN DV
• What threats to internal validity (confounds)
  does the design control for? MATURATION HISTORY
• Ethical issues? ENDS ON BASELINE

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The ABABABAB Withdrawal (Repeated Reversal)
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When to Use the ABAB Withdrawal (Repeated
Reversal)

• When you need to observe a functional
  relationship (otherwise you can use the AB
  design)
• When the effects of IV (intervention) do not
  remain in the DV
• When ethics allow this design. If it is NOT
  ethical to remove treatment, then dont use a
  withdrawal design

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Adaptations of Withdrawal designs BAB design

• Better from an ethical standpoint because client
  or learner gets intervention right away and ends
  on treatment
• Worse than ABA design from a control standpoint
  because we dont know pre-intervention levels
  (BAB has slightly lower internal validity than
  ABA)

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Adaptations of Withdrawal designs ABC (Changing
Conditions) design

• Used when treatment B tanks and you switch to a
  new treatment C
• Introduces an unwanted possible confound of
  order/sequence effects (Maybe C only works if it
  follows B!)
• Has poor internal validity but is very similar to
  how we provide treatment in real world.
• Can be improved if we use(see next)gtgt

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Adaptations of Withdrawal designs ABAC
(Multiple Treatments) design

• Allows better chance to see functional
  relationship
• Has better internal validity
• Can be improved even more if we use ABACA (with
  added C phase)

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End