Skills Assessed: Behavior Assessment
Section B of the RBT Task List 3.0 covers Behavior Assessment. During your competency assessment, your BCBA assessor will evaluate your ability to conduct preference assessments, define behaviors operationally, and identify antecedents that trigger behavior.
This is a practical skills test — the assessor watches you work with a client (or role-play scenario) and checks that you can perform each task competently. You must demonstrate 3 key skills: conducting preference assessments, defining behavior operationally, and identifying antecedents. Here's exactly what to expect and how to prepare.
Skills Assessed: Behavior Assessment
1. Conducting Preference Assessments
Your assessor will ask you to conduct a preference assessment to identify potential reinforcers for the client. You must choose the correct method (MSWO, MSW, or Paired Stimulus) based on the client's needs and abilities.
Example: You lay out 5 toys and ask the client to rank them by preference (MSWO — Multiple Stimulus Without Replacement). The client picks a toy, you remove it, then they pick from the remaining 4, and so on. You record the order: 1st = highest preference, 5th = lowest preference. The assessor checks that you followed the correct procedure and recorded results accurately.
2. Defining Behavior Operationally
You must write an operational definition of a target behavior that is observable and measurable — something that can be seen or heard, not an opinion or feeling.
Example: "Hitting = striking another person with open hand with enough force to make a sound or leave a mark." This is observable (you can see the hand strike and hear the sound). Compare to the non-operational definition: "Aggression" — this is vague and open to interpretation. The assessor checks that your definition is specific, observable, and measurable. Every RBT must be able to write operational definitions for the behaviors they track.
3. Identifying Antecedents
Antecedents are events that happen BEFORE a behavior occurs. Your assessor will ask you to identify antecedents during a session or from a description of a behavior incident.
Example: During a session, every time a math worksheet is placed in front of the client, they scream and throw the pencil. The antecedent = "math worksheet presented." The behavior = screaming and throwing pencil. The consequence = worksheet removed. The assessor checks that you can correctly identify what happened BEFORE the behavior (the antecedent) and understand the ABC (Antecedent-Behavior-Consequence) sequence. This is foundational for understanding why behaviors occur.
Supervisor Competency Checklist (Behavior Assessment)
Your BCBA assessor uses this checklist to sign off on your behavior assessment skills. Print this and review with your supervisor BEFORE the official assessment.
Preference Assessment Methods
RBTs use preference assessments to identify what items/activities may function as reinforcers for their client. Each method has different procedures, advantages, and drawbacks.
Operational Definition Example
The assessor will ask you to write an operational definition for a target behavior. It must be observable (can be seen/heard) and measurable (can be counted or timed).
Correct (Observable & Measurable): "Hitting = striking another person with open hand with enough force to make an audible sound or leave a visible mark."
Incorrect (Vague / Opinion): "Aggression = when the client is angry and tries to hurt someone." (Too vague — "angry" is not observable)
Another Correct Example: "Raising hand = elbow leaves desk surface and hand is raised above shoulder level."
Key Takeaways
• 3 skills assessed: Preference assessments, operational definitions, identifying antecedents.
• MSWO = rank order (remove picked item). MSW = frequency count (return picked item).
• Paired Stimulus = 2 items at a time, all possible pairs. Most accurate but slowest.
• Operational definition must be observable ("can be seen/heard") and measurable.
• Antecedent = what happens BEFORE the behavior. Master the ABC sequence.
• Section B (Behavior Assessment) = ~12% of RBT exam (10–11 questions).
Conclusion
Behavior Assessment is a critical section of your RBT competency assessment. Your BCBA assessor wants to see that you can identify what motivates your client (preference assessments), define behaviors so anyone can measure them (operational definitions), and understand what triggers behavior (antecedents).
Practice all 3 preference assessment methods with your supervisor before the assessment. Write 5 operational definitions for common behaviors (hitting, screaming, raising hand, on-task, elopement) and have your BCBA review them. And memorize the ABC sequence: Antecedent → Behavior → Consequence. Master these, and you'll pass the Section B portion of your competency assessment with confidence.