ABA Exam Coach

D.2: Distinguish between internal and external validity.

Free practice questions for this part of the BCBA, with an explanation for every option.

An ABAB reversal design run in a clinic clearly shows that a self-monitoring procedure improved an adolescent's on-task behavior. His parents ask whether the procedure will also work when they use it at home. Their question is mainly about:
  1. A. Interobserver agreement
    Incorrect. IOA tells you how believable the measurement is. It does not tell you whether results generalize.
  2. B. Internal validity
    Incorrect. Internal validity is about whether the independent variable, and not something else, produced the change in this study. The clinic data already establish that.
  3. C. Treatment integrity
    Incorrect. Treatment integrity is about whether the procedure was carried out as planned. It does not tell you whether effects hold in a new setting.
  4. D. External validity
    Correct. External validity is about generality: whether a functional relation holds across other settings, people, or behavior change agents, such as parents at home.
A researcher wants to strengthen the INTERNAL validity of a study showing that a visual schedule reduces transition-related tantrums for one child. Which addition would help most?
  1. A. Teaching the child's grandparents to use the schedule on weekends
    Incorrect. Extending use to new caregivers is a question about generalization, not about whether the schedule caused the change.
  2. B. Surveying the child's teachers about whether they find the schedule acceptable
    Incorrect. Social validity data tell you how acceptable the intervention is. They do not show a functional relation.
  3. C. Running the same procedure with three other children at different schools
    Incorrect. Replicating with other children in other schools mainly speaks to generality (external validity), not to control within this child's data.
  4. D. Adding another withdrawal and reintroduction of the visual schedule with the same child
    Correct. Each additional demonstration that behavior changes when the schedule is withdrawn and reintroduced makes confounding variables less likely and strengthens experimental control.
A BCBA working in organizational behavior management starts daily graphed feedback for forklift operators at one distribution center. A reversal design shows that safety-checklist completion rises reliably whenever feedback is in place. The regional director asks whether the same feedback will work at the company's other four centers. The director's question is mainly about:
  1. A. The external validity (generality) of the finding
    Correct. External validity is the extent to which a functional relation holds across other participants, settings, and conditions. Asking whether the result will hold at other centers is a question about generality.
  2. B. The internal validity of the reversal design
    Internal validity is about whether feedback, and not some other variable, caused the change at the original center. The reversal design already addressed that. The director is asking about other sites.
  3. C. The treatment integrity of the feedback procedure
    Treatment integrity is about whether the feedback was delivered as planned. The director is not questioning how it was delivered at the first center.
  4. D. The social validity of the safety-checklist goal
    Social validity is about whether goals, procedures, and outcomes are acceptable and important to consumers. The director is asking whether the effect will replicate elsewhere, not whether the goal is worthwhile.

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