Question
Difficulty: medium. Skill: apply. Type: experimental design critique.
A BCBA is evaluating whether an intervention changed leaving the instructional area. A second program change began during the same week. Which concern best reflects internal and external validity? The case file includes 2 recent sessions, 1 implementer, and 3 settings.
ABase the decision on the descriptive label for leaving the instructional area and bypass internal and external validity
BUse a familiar protocol even though it does not address measurement quality and procedural integrity
CCheck measurement quality, observer agreement, and procedural integrity before making a major decision in relation to learner's leaving the instructional areaCorrect answer
DRely on caregiver's report alone and stop collecting direct evidence
Explanation
Answer CThe clue is the combination of four sessions of stable baseline data followed by two overlapping intervention points, leaving the instructional area, and the required task: Internal and external validity. The case file includes 2 recent sessions, 1 implementer, and 3 settings. Check measurement quality, observer agreement, and procedural integrity before making a major decision in relation to learner's leaving the instructional area is best because it answers that clue through measurement quality and procedural integrity instead of treating the scenario as a generic behavior problem. On exam items like this, name the decision point first, then eliminate options that rely on one report, a label, a familiar protocol, or an action that skips the relevant data check.
Why this question is hard
ClueKey scenario clueThe clue is the combination of four sessions of stable baseline data followed by two overlapping intervention points, leaving the instructional area, and the required task: Internal and external validity. The case file includes 2 recent sessions, 1 implementer, and 3 settings.
TrapCommon trapThis is weaker because the label does not answer the Internal and external validity decision point or test Measurement quality and procedural integrity.
NextIf you missed it, review Internal validity and confoundsThen answer a few related scenarios before moving back to broad practice.
Why the other choices are weaker
AChoice AThis is weaker because the label does not answer the Internal and external validity decision point or test Measurement quality and procedural integrity.
BChoice BA familiar protocol is not enough unless it matches the assessed variables and the current decision question.
DChoice DStakeholder input matters, but direct data, context, and integrity checks are still needed for a defensible answer.
Study tags
Measurement quality and procedural integrityInternal and external validityvalidityreliability
Related concept pages
Turn this into a study plan
If this question felt difficult, practice a short drill from Experimental Design and use the review page to turn missed items into a weak-area plan.
Practice interactively
Try more BCBA scenario questions in the interactive practice mode, then use review tools to track missed domains and flagged items.