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The BCBA exam's applied block rewards one workflow: assess → hypothesize function → match the intervention → choose measurement → monitor integrity. This article gives you eight original cases that isolate each step. Every case states its assumptions explicitly, and the rationales explain why the best answer is best and why the distractors fail. For the underlying exam map, see the BACB sixth-edition Test Content Outline. For a larger practice set, go to the free BCBA practice page.
Scope disclaimer. These cases are written for exam reasoning practice, not as templates for real clinical decisions. A real behavior analyst would confirm hypotheses with direct assessment, consider assent and contextual fit, and tailor every plan to the individual and setting.
Functional assessment pathways
The BCBA exam expects you to choose among indirect, descriptive, and functional analysis methods based on the referral question, resources, risks, and what is already known.
| Pathway | What it gives you | When it is most appropriate |
|---|---|---|
| Indirect assessment | Reports, histories, and ratings from caregivers or records (interviews, questionnaires). | Early in the process, when you need hypotheses quickly, or when direct observation is not yet possible. |
| Descriptive assessment | Direct observation of antecedents, behavior, and consequences in the natural environment (ABC recording, scatterplot, interval recording). | When you need to see whether patterns in the natural environment match the indirect hypotheses. |
| Functional analysis | Experimental manipulation of antecedents and consequences to test which condition produces the behavior. | When hypotheses remain unclear, when risk is low enough to evoke the behavior, and when resources allow controlled sessions. |
A common exam trap is choosing functional analysis first because it is "more precise." Precision is only one criterion. If an indirect or descriptive assessment already points clearly to one function, or if evoking the behavior would be unsafe, a functional analysis may not be the next step. Another trap is confusing the form of the behavior (what it looks like) with its function (why it persists). Two topographically different behaviors can serve the same function, and the same topography can serve different functions across people or contexts.
From function to intervention
Function-matched intervention is the testable skill in Areas G and H. The procedure must address the reinforcer that maintains the behavior, not just suppress the behavior's form.
- Attention function: teach and reinforce a functionally equivalent or alternative communicative response to request attention; arrange attention for the replacement behavior and remove attention for the target behavior when safe.
- Escape/avoidance function: teach a request for break or help; modify task difficulty or duration; use escape extinction carefully while ensuring the learner has a viable alternative.
- Tangible function: teach a request for the item or activity; use delayed or contingent access rather than immediate compliance-driven access; consider tolerance training when appropriate.
- Automatic/sensory function: provide matched alternative sensory input or modify the environment so the same stimulation is available without the target behavior; monitor because automatic reinforcement is harder to remove directly.
Before selecting any procedure, ask three questions on the exam: (1) What is the hypothesized maintaining consequence? (2) Does the proposed intervention deliver that consequence for a replacement behavior or remove it for the target behavior? (3) Is the intervention feasible and consistent with the least-restrictive-effective alternative?
Choosing between procedures
Area G often tests the distinctions among differential reinforcement procedures and the conditions for using extinction or punishment.
| Procedure | Core contingency | Typical use case |
|---|---|---|
| DRA (differential reinforcement of alternative behavior) | Reinforce a specified alternative behavior; reinforcement favors the alternative behavior; withholding the maintaining reinforcer from the target is an additional extinction component when used. | A functionally equivalent request replaces the problem behavior (e.g., raise hand instead of shouting out). |
| DRI (differential reinforcement of incompatible behavior) | Reinforce a behavior that cannot physically occur at the same time as the target behavior. | Hands-in-lap instead of hitting; sitting instead of running. |
| DRO (differential reinforcement of other behavior) | Reinforce the absence of the target behavior for a specified interval. | Reducing disruptive vocalizations during a class period. |
| Extinction | Withhold the previously maintaining reinforcer for the target behavior. | Attention, escape, or tangible functions where the reinforcer is under the interventionist's control. |
Punishment procedures can reduce behavior, but the exam consistently tests least-restrictive-alternative reasoning: choose the effective intervention that preserves the most learning opportunities and minimizes aversive control. Extinction is not risk-free either. When you withhold a powerful reinforcer, monitor for a possible extinction burst (a temporary increase in frequency, intensity, or variability) and possibly extinction-induced emotional responding. Plan for those before starting.
Worked cases
Each case below is original and self-contained. Read the scenario, choose the best answer, then review the rationale. The cases are not clinical protocols; they are simplified exam-style reasoning exercises.
Case 1: Identifying an attention function
Scenario. During group activities, a learner screams loudly whenever the instructor talks to another student. Screaming stops within seconds after the instructor turns to the learner and says, "Stop." The behavior rarely occurs during one-to-one instruction, and it almost never occurs when the learner is alone in a quiet room.
Question. Based on the ABC pattern described, what is the most likely function of the screaming?
- A. Automatic/sensory reinforcement
- B. Escape from the group activity
- C. Access to a tangible item
- D. Access to attention from the instructor
Answer: D. The behavior occurs in the presence of another student receiving attention (antecedent), produces immediate instructor attention (consequence), and stops once attention is delivered. The low rate during one-to-one instruction and when alone further supports attention, not escape or automatic reinforcement. Tangible access (C) is unsupported because no item is mentioned.
Case 2: Function-matched intervention for escape
Scenario. A learner pushes materials off the table when given multi-step math worksheets. Pushing stops as soon as the worksheet is removed and the learner is directed to a preferred break area. A descriptive assessment shows the behavior occurs almost exclusively when task demands are high, not when demands are absent.
Question. Which intervention best matches the hypothesized function?
- A. Provide a preferred edible after every correct response
- B. Teach the learner to request a break and initially reinforce the request and adjust demands and any later schedule thinning to assessment and safety
- C. Remove all math worksheets from the curriculum
- D. Deliver a brief reprimand each time materials are pushed
Answer: B. The maintaining consequence appears to be escape from the demand. Teaching a functionally equivalent break request gives the learner a way to obtain escape appropriately, while task demands can be reintroduced and faded over time. Option A targets tangible reinforcement, not escape. Option C removes the demand entirely and does not teach a replacement skill. Option D is a punishment-oriented response that ignores the escape function.
Case 3: Tangible function and differential reinforcement
Scenario. At a store checkout, a child cries and reaches toward the candy display whenever candy is denied. Crying stops within seconds after the caregiver gives the child a piece of candy. Staff report the behavior is rare when no candy is visible.
Question. Which combination is the most appropriate first-line approach?
- A. Teach and reinforce an appropriate request for candy, with an individualized plan for availability and waiting
- B. Extinction only: ignore crying and never provide candy
- C. Provide candy before any crying occurs to prevent the behavior
- D. Remove the child from the store whenever crying begins
Answer: A. Access to candy is a hypothesis supported by the described consequence, not a demonstrated function. Teaching and reinforcing a request is a DRA/FCT approach; merely teaching a request alongside DRO does not establish reinforcement for that request. B omits replacement-skill teaching. C alone does not teach communication, though noncontingent access can be part of a broader plan. D does not teach an alternative and changes several conditions at once.
Case 4: Automatic/sensory function
Scenario. A learner repeatedly flicks fingers near the eyes while sitting alone during break times. The behavior occurs whether or not anyone else is present, and it persists even when preferred items and attention are freely available. There is no change in the environment after the behavior occurs.
Question. What is the most likely function, and which assessment would best test it?
- A. Attention function; test with an attention condition in a functional analysis
- B. Escape function; test with a demand condition in a functional analysis
- C. Automatic reinforcement; consider a safely monitored alone/ignore condition within a qualified functional assessment
- D. Tangible function; test with a tangible condition in a functional analysis
Answer: C. Persistence without social consequences supports an automatic-reinforcement hypothesis. A qualified, safely monitored functional assessment can test it; the descriptive observations alone do not establish function. The other options test social hypotheses less supported by this stem. Harmless self-stimulation does not automatically require reduction.
Case 5: Choosing a measurement system
Scenario. A behavior analyst is asked to evaluate a learner's on-task behavior during 20-minute independent work periods. The behavior is continuous when it occurs but starts and stops unpredictably. The team wants to know how much of the period the learner spends on task.
Question. Which measurement system best fits the stated goal?
- A. Frequency count of on-task responses
- B. Duration recording of on-task behavior
- C. Latency from instruction to first on-task response
- D. Inter-response time between on-task episodes
Answer: B. The team wants to know how much of the period is spent on task, which is a duration question. Frequency (A) would count episodes but miss how long each lasts. Latency (C) measures the time from a prompt to behavior onset. Inter-response time (D) measures the time between responses and does not capture total time on task.
Case 6: Spotting an intervention-integrity risk
Scenario. A teacher is implementing a DRA procedure in which a learner earns attention for raising a hand and attention is withheld for calling out. After two weeks, data show little improvement. During a classroom observation, the behavior analyst notices that the paraprofessional sometimes responds to the learner's call-outs with eye contact and reminders to "use your hand."
Question. What is the most likely explanation for the lack of progress?
- A. The DRA procedure is matched to the wrong function.
- B. The replacement behavior is not in the learner's repertoire.
- C. The target behavior continues to be reinforced intermittently by staff.
- D. The learner is satiated on attention.
Answer: C. The paraprofessional is delivering attention for calling out, which undermines extinction and makes the DRA less effective. Intermittent reinforcement can make a behavior more resistant to change than continuous reinforcement. The scenario gives no evidence that the function is wrong (A), that the replacement behavior is missing (B), or that the learner is satiated on attention (D).
Case 7: Least-restrictive-alternative reasoning
Scenario. A learner engages in hand-biting that produces mild tissue damage. A functional analysis indicates the behavior is maintained by automatic reinforcement. A noncontingent sensory schedule and protective equipment have already been tried with limited success. The team is considering a brief contingent application of an aversive taste gel after each episode.
Question. Before implementing the taste gel, what should the behavior analyst prioritize?
- A. Increase the intensity of the taste gel to ensure suppression.
- B. Document that less-restrictive alternatives were attempted and evaluate additional reinforcement-based options.
- C. Implement the gel immediately because tissue damage justifies any effective punishment.
- D. Discontinue all protective equipment to test whether the gel alone is sufficient.
Answer: B. Document prior treatment, assess medical contributors and risks, and evaluate reinforcement-based alternatives with qualified oversight, consent, and ongoing data review. Documentation alone does not authorize an aversive procedure. A and C escalate risk without safeguards; D removes protection without justification.
Case 8: From assessment data to hypothesis
Scenario. Caregivers report that a learner hits peers during transitions between activities. Direct observation shows the behavior occurs when the learner is asked to stop a preferred activity and move to a less preferred one. Peers move away, and the learner is allowed to remain at the preferred activity for a few extra minutes while staff redirect the other children. The behavior is rare when the learner chooses the next activity.
Question. Which hypothesis and matched intervention are most consistent with the data?
- A. Attention function; use DRO for no peer contact and provide attention for compliance.
- B. Escape/avoidance of transition; use a visual schedule and pre-activity warning plus a break request.
- C. Tangible function; provide continuous access to preferred activities all day.
- D. Automatic function; provide alternative sensory input during transitions.
Answer: B. The behavior is evoked by transition demands and produces delay/avoidance of the transition, suggesting an escape/avoidance function. A visual schedule, warning, and functionally equivalent break request address that function. The observations may also suggest continued preferred-activity access, so assess competing or multiple functions. Attention (A) is less supported by the stated consequences. Continuous preferred access (C) is not a transition intervention. Automatic reinforcement (D) is unsupported because the behavior is tied to a specific environmental transition.
How to use these cases in your study plan
Do not memorize "screaming = attention" or "worksheet refusal = escape." Those are form-based shortcuts, and the exam will punish you for using them. Instead, practice naming the antecedent, the behavior, and the consequence in every scenario, then ask what reinforcer those consequences deliver.
- Assess the data source first. Is the scenario giving you indirect report, descriptive ABC data, or functional-analysis results? Each source has different limitations.
- Separate topography from function. The same behavior can serve different functions in different contexts; the exam tests whether you notice the context.
- Match before suppressing. Use the function hypothesis, client goals, and outcome data to evaluate intervention fit; the scenario does not establish a universal prediction about durability.
- Check integrity and ethics. If a scenario describes poor implementation, team disagreement, or a restrictive procedure, the correct answer often addresses integrity, training, or least-restrictive-alternative reasoning rather than a new intervention.
For more practice, use the free BCBA practice questions. For the big-picture exam structure, review the BACB sixth-edition Test Content Outline.
References
- [1] Behavior Analyst Certification Board (2022). BCBA Test Content Outline, 6th Edition. BACB; sixth edition, updated September 2024. BACB; sixth edition, updated September 2024
- [2] Behavior Analyst Certification Board (2026). BCBA Handbook. bacb.com. bacb.com
- [3] Behavior Analyst Certification Board (2022). Ethics Code for Behavior Analysts. bacb.com. bacb.com
- [4] Cooper, J. O., Heron, T. E., & Heward, W. L. (2020). Applied Behavior Analysis, 3rd Edition. Pearson.
- [5] Hanley, G. P. (2012). Functional Assessment of Problem Behavior: Dispelling Myths, Overcoming Implementation Obstacles, and Developing New Lore. Behavior Analysis in Practice. Behavior Analysis in Practice
Frequently asked questions
Per the BACB 6th edition Test Content Outline, Area F (Behavior Assessment) is about 13% of scored questions, Area G (Behavior-Change Procedures) is about 14%, and Area H (Selecting and Implementing Interventions) is about 11%. Together they make up roughly 38% of the 175 scored items.
DRA reinforces an alternative behavior that may or may not be physically incompatible with the target behavior. DRI reinforces a behavior that cannot occur at the same time as the target behavior. DRO reinforces the absence of the target behavior during a specified interval. The exam often tests which procedure fits a given scenario.
Extinction may be a poor first choice when the function is automatic (the reinforcer is not under the interventionist's control), when the behavior is dangerous and evoking a burst would be unsafe, when procedural integrity cannot be guaranteed across all caregivers, or when no replacement behavior has been taught.
Real behavior-analytic work requires assessment, contextual fit, assent, and ongoing monitoring. These cases are simplified exam exercises. Stating assumptions keeps the rationales tied to the information given and avoids presenting a scenario as a universal clinical rule.
The BCBA exam and the BACB ethics code emphasize least-restrictive-effective alternatives. Punishment may be considered when reinforcement-based approaches have been insufficient and the risk of the target behavior is high, but it requires informed consent, oversight, documentation of less-restrictive alternatives, and a plan to teach replacement skills.
Match the measurement to the dimension of interest. Use frequency or rate when the question is "how often." Use duration when the question is "how long." Use latency when the question is "how long until the behavior starts after a prompt." Use percentage or trials correct when the question is accuracy. The exam often hides the dimension inside the wording of the goal.
Keep practicing BCBA assessment and intervention reasoning
Try the free BCBA question sampler, then use the explanations to choose what to review next. This is a short practice set, not a full-length exam.
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