Defining features of single-case experimental designs: Single-case design selection.
Original BCBA scenario practice question with answer explanation and wrong-choice notes. Not an official BACB exam item. Last machine check: 2026-07-05.
A decrease in leaving the work area occurs during the same week that staff change prompts, reinforcement, and session length. Across 6 sessions in service week 26, one observer recorded 29 minutes of observation in the early intervention clinic. Before claiming the intervention caused the change, the BCBA should:
A
Use a design that can show experimental control without withdrawing a needed or unsafe intervention.
Correct answer
B
Use a simple pre-post comparison and describe any improvement as experimental control.
C
Withdraw an effective safety procedure to make the graph easier to interpret.
D
Start several changes at once and attribute later improvement to the preferred component.
Content quality status
machine gate passed
Orig
Original study item
This question was created for BCBA Scenario Tutor. It is not an official, leaked, or copied BACB exam question.
Chk
Automated validation passed
The item includes an answer key, explanation, wrong-choice notes, domain label, concept tags, and source notes. Automated checks cover structure, coverage, and consistency only. No named, credential-verifiable BCBA external review has occurred, and this is not a clinical or exam-validity certification.
Date
Last machine check: 2026-07-05
Source note: Original v2 item upgraded from internal task/concept map; not copied from official or commercial question banks.
A concise review block for candidates and answer engines.
Fact
What this question tests
Defining features of single-case experimental designs: Single-case design selection. in Experimental Design, with study tags for Single-case design selection, Defining features of single-case experimental designs, reversal design, multiple baseline.
Fact
Best review move
Before reading the explanation, choose an answer and name the scenario clue. If you missed it, review Single-case design selection and try similar questions in this domain.
Fact
Content boundary
This is an original study item for BCBA Scenario Tutor, not an official BACB exam question or a copied exam item.
The decision point is: Does the answer protect experimental control and avoid unsupported causal claims? This item specifically tests Defining features of single-case experimental designs through a data-review-scenario format. The key clue is in the stem facts: A decrease in leaving the work area occurs during the same week that staff change prompts, reinforcement, and session length. Across 6 sessions in service week 26, one observer recorded 29 minutes of observation in the early intervention clinic. Before claiming the intervention caused the change, the BCBA should: Answer A is strongest because it follows this rule: Use a design that can show experimental control without withdrawing a needed or unsafe intervention. It fits the source-backed rule without announcing that rule in the stem. The tempting mistake is to choose a shortcut before the scenario's prerequisite is satisfied. This choice weakens the data basis for the decision. A defensible answer must check whether the measurement, observation, or visual-analysis evidence supports the next step. Exam move: name the missing prerequisite first, then eliminate answers that jump to a label, a familiar procedure, a single data point, or an undocumented action.
Turn this into a study plan
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A decrease in leaving the work area occurs during the same week that staff change prompts, reinforcement, and session length. Across 6 sessions in service week 26, one observer recorded 29 minutes of observation in the early intervention clinic. Before claiming the intervention caused the change, the BCBA should:
Trap
Common trap
This choice weakens the data basis for the decision. A defensible answer must check whether the measurement, observation, or visual-analysis evidence supports the next step.
Next
If you missed it, review Single-case design selection
Then answer a few related scenarios before moving back to broad practice.
Exam-style review notes
Structured study guidance maintained by Bifang Studio's internal editors and automated quality checks.
v4-machine-content-gate
Rule
Defining features of single-case experimental designs: Single-case design selection
Does the answer protect experimental control and avoid unsupported causal claims?
Clue
What the stem gives you
A decrease in leaving the work area occurs during the same week that staff change prompts, reinforcement, and session length. Across 6 sessions in service week 26, one observer recorded 29 minutes of observation in the early intervention clinic. Before claiming the intervention caused the change, the BCBA should:
Trap
Common trap
AB design with no replication. This often shows up as using reversal for irreversible skills..
Fix
If you missed this item
Rewrite the miss as a rule: "When I see Single-case design selection, I must identify the relevant evidence before choosing the action." Then answer two related D domain questions without reading explanations first.
Next
Next drill
Practice 3 more questions tagged to Single-case design selection, then explain why each wrong answer is weaker before moving back to mixed practice.
Source-aware internal editorial maintenance using src-bacb-bcba-tco-6ed for study organization; not an official BACB item and not externally reviewed by a named, verifiable BCBA.
Why the other choices are weaker
B
Choice B
This choice weakens the data basis for the decision. A defensible answer must check whether the measurement, observation, or visual-analysis evidence supports the next step.
C
Choice C
This choice weakens the data basis for the decision. A defensible answer must check whether the measurement, observation, or visual-analysis evidence supports the next step.
D
Choice D
This choice is weaker because it does not resolve the key prerequisite in the scenario: a decrease in leaving the work area occurs during the same week that staff change prompts, reinforcement, and session length. Across 6 sessions in service week 26, one observer recorded 29 minutes of observation in the early intervention clinic. Before claiming the intervention caused the change, the BCBA should:
Study tags
Single-case design selectionDefining features of single-case experimental designsreversal designmultiple baseline
This practice question is tagged to Experimental Design. It also includes study tags for Single-case design selection, Defining features of single-case experimental designs, reversal design, multiple baseline.
How should I review this practice question?
Answer the scenario before reading the explanation, compare your reasoning with the correct answer, then review why the distractors are weaker.
Is this an official BACB exam question?
No. This is an original study question for BCBA Scenario Tutor and is not an official BACB exam item.
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Published by Bifang Studio. Content is maintained by internal editors with automated structure, coverage, and consistency checks. No content has been externally reviewed by a named, credential-verifiable BCBA; these checks do not certify clinical quality or exam validity.