Master the BCBA Exam: 10 Hard Practice Questions & Clinical Deep Dives

Preparing for the BCBA exam requires more than just memorizing definitions; it requires the ability to apply behavioral principles to complex, real-world scenarios. This blog post breaks down 10 "hard" difficulty practice questions covering measurement, ethics, personnel management, and experimental design.

Test your knowledge below!

Part 1: Measurement & Experimental Design

1. Choosing the Right Measurement System

Scenario: Marcus is facilitating a social skills dyad. One client, Leo, engages in vocal stereotypy 6–8 times per minute. Marcus is actively teaching and cannot observe Leo continuously. He needs a measurement system that won't hit a "ceiling effect" (100% occurrence) just because the behavior is high-rate.

Question: Which measurement system is most appropriate?

• A) Partial interval recording

• B) Whole interval recording

• C) Event recording using a hand-tally counter

• D) Momentary time sampling

Correct Answer: D

Rationale: Momentary time sampling is practical for busy clinicians because it only requires looking at the client at the very end of an interval. Unlike Partial Interval Recording (PIR), it avoids the "ceiling effect" where high-rate behaviors saturate every interval, providing a more accurate trend over time.

2. Analyzing Confounding Variables

Scenario: A BCBA is using a multiple baseline design across settings (home, school, after-school) to track SIB. After starting the intervention at home, the client is prescribed a new medication. Suddenly, SIB drops significantly across all settings simultaneously.

Question: Which confounding variable best explains this shift?

• A) Sequence effects

• B) Maturation

• C) Observer drift

• D) History

Correct Answer: D

Rationale: "History" refers to an extraneous event (the medication change) occurring concurrently with the study that produces changes across all tiers. This violates the logic of a multiple baseline design, as changes should only occur where the intervention is active.

Part 2: Personnel Supervision & OBM

3. Skill Deficit vs. Performance Deficit

Scenario: An RBT's fidelity on preference assessments dropped from 100% to 75%. In a role-play with no client, he performs perfectly. A Performance Diagnostic Checklist (PDC-HS) reveals he hasn't received feedback recently and there are no consequences for performance.

Question: Which intervention is most appropriate?

• A) Remedial 1:1 behavioral skills training (BST)

• B) Laminated step-by-step checklists in the binder

• C) Formal corrective action plan for non-compliance

• D) Weekly graphic feedback system and descriptive praise

Correct Answer: D

Rationale: Since the RBT can perform the task flawlessly in role-play, this is a performance deficit, not a skill deficit. Adding consequences like feedback and graphic displays addresses the "Performance Consequences" domain of the PDC-HS.

Part 3: Concepts & Principles

4. Stimulus vs. Response Generalization

Scenario: Elias is taught to open jars using a rubber grip pad. Later, presented with the same jar, he instead uses a spoon to tap the lid and break the seal, then opens it with his bare hands.

Question: Which principle best accounts for this?

• A) Stimulus generalization

• B) Stimulus discrimination

• C) Maintenance

• D) Response generalization

Correct Answer: D

Rationale: Response generalization occurs when a learner emits a novel, untrained behavior (using a spoon) that serves the same function as the trained behavior in the presence of the same stimulus (the jar).

5. Identifying Resurgence

Scenario: Leo’s aggression was treated with Functional Communication Training (FCT) on an FR1 schedule. When the BCBA thinned the schedule to a VR5, Leo’s aggression suddenly returned at high intensity.

Question: What is this phenomenon?

• A) Delayed extinction burst

• B) Spontaneous recovery

• C) Escalation crisis

• D) Resurgence

Correct Answer: D

Rationale: Resurgence is the re-emergence of a previously extinguished behavior when the reinforcement for a more recently acquired alternative behavior is thinned or removed.

Part 4: Ethics & Assessment

6. Managing Multiple Relationships

Scenario: A BCBA in a rural area realizes his child is in the same tiny private school class as his client. The school requires weekly joint parent-student workshops. The client has severe SIB and local waitlists are 60+ days long.

Question: What is the ethical course of action?

• A) Terminate services immediately to avoid the conflict.

• B) Have the family sign a waiver to keep social/professional roles separate.

• C) Delegate implementation to an RBT to create a buffer.

• D) Disclose the conflict, seek consultation, and develop a transition plan.

Correct Answer: D

Rationale: The BACB Ethics Code requires resolving conflicts while preventing client abandonment. Abruptly stopping services for severe SIB is dangerous; a structured transition to a new provider is required.

7. Interpreting Functional Analysis (FA) Data

Scenario: A client with a history of slow stimulus control acquisition shows high-rate head-banging across all FA conditions, including the control (toy play) condition.

Question: What is the best next step?

• A) Interpret this as an automatic reinforcement function.

• B) Conclude the behavior is multiply maintained.

• C) Terminate the FA because the behavior is "naturally occurring."

• D) Shift to a pairwise or extended-duration design.

Correct Answer: D

Rationale: Undifferentiated data in a multielement FA often results from carryover effects or a failure to discriminate between rapidly changing conditions. A pairwise design gives the client more time to contact the specific contingencies of each condition.