Functional analysis
A functional analysis systematically manipulates antecedents and consequences in test and control conditions to show which variables maintain a problem behavior.
In a functional analysis (FA), the behavior analyst arranges conditions that each test one possible function, and compares rates of problem behavior across them. A common set includes an attention condition (attention is given briefly after problem behavior), an escape or demand condition (demands are removed briefly after problem behavior), a tangible condition (a preferred item is returned after problem behavior), an alone or no-interaction condition (to test automatic reinforcement), and a play or control condition (free access to attention and items, no demands). Conditions are repeated across sessions and graphed.
If behavior is consistently higher in one test condition than in the control condition, that suggests the behavior is maintained by the consequence delivered in that condition. Because the variables are manipulated directly, FA can demonstrate a functional relation, which indirect and descriptive methods cannot. Variations, such as brief or trial-based FAs, adapt the method to different settings.
FA sessions deliberately evoke problem behavior, so they require careful planning, safety precautions, clear stopping criteria, and the consent of the client's caregivers. They are designed and closely supervised by a qualified behavior analyst. RBTs may implement conditions as trained and record data, following the protocol exactly, including how quickly and in what form the consequence is delivered.
Example and non-example
| Example | Under the supervisor's direction, an RBT runs 5-minute attention, demand, alone and play conditions in rotating order and records each instance of head hitting, which occurs mainly in the demand condition. |
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| Non-example | Watching a client during lunch and writing down what happened before and after each outburst is a descriptive assessment, because nothing is manipulated. |
Don't confuse it with
| Functional behavior assessment | Functional analysis is one experimental method; an FBA is the broader process that may include indirect and descriptive methods too. |
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| Descriptive assessment | Functional analysis manipulates variables to show causes; descriptive assessment observes without manipulating and shows only correlations. |
Test yourself
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Question 1Which list names the three general types of functional assessment methods?
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A: Indirect assessment, descriptive assessment and functional analysis. Functional assessment includes indirect methods (interviews, rating scales), descriptive methods (direct observation in the natural setting, such as ABC data) and functional analysis (testing conditions directly).
- B: These are other kinds of assessments, not functional assessment methods.
- C: These are continuous measurement procedures.
- D: These are phases of intervention, not assessment methods.
Task B.3 · 40-hour curriculum section D
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Question 2Which statement describes a functional analysis?
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D: Antecedents and consequences are arranged on purpose to test their effects. In a functional analysis, the team arranges test and control conditions and measures how often the problem behavior occurs in each, which shows which consequences maintain it.
- A: A caregiver rating scale is an indirect assessment.
- B: Observing without changing anything is descriptive assessment.
- C: Choosing among items to rank them is a preference assessment.
Task B.3 · 40-hour curriculum section D
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Question 3Why is a functional analysis considered stronger evidence of function than ABC observation?
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A: It changes conditions directly, so it can show cause, not just correlation. ABC observation shows which events tend to occur with the behavior. A functional analysis changes the conditions on purpose and measures the behavior, so it can demonstrate a functional relation.
- B: A functional analysis measures behavior directly; it does not rely on caregiver reports.
- C: Functional analyses are usually conducted in controlled settings with planned conditions.
- D: A functional analysis depends on careful measurement of the behavior in each condition.
Task B.3 · 40-hour curriculum section D
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On the RBT exam
This term belongs to task B.3 Functional assessment in content area B, Behavior Assessment, which is 8 of the 75 scored questions.