Interviews and records tell you what other people have noticed or reported about a behavior. A descriptive assessment lets you see it for yourself. You watch the behavior where it actually happens, in the classroom, the kitchen, or the day program, and write down what comes before and after it. Nothing is changed or arranged. You simply describe.
Why it matters
Descriptive assessment sits between indirect assessment (interviews, rating scales, records) and functional analysis in a typical functional behavior assessment. It gives you real data on when, where, and around whom behavior occurs. That helps you form sharper hypotheses, choose conditions for a functional analysis, and pick the best times to observe.
The skills to practice are naming a method from a description, choosing a tool for a stated purpose, and, above all, recognizing what descriptive data cannot tell you.
Key ideas
- Direct, but not experimental. You observe the behavior and the natural events around it as they occur. Because you do not manipulate any variable, the data show correlations, not functional relations.
- It builds hypotheses. Patterns in descriptive data suggest which antecedents and consequences might matter. You confirm a function only by showing control, usually with a functional analysis.
- Define the behavior first. Observers need an operational definition so every recorder counts the same thing. Check interobserver agreement when you can.
- Sample enough. One or two short observations can miss a pattern. Observe across days, activities, and people, and include the times caregivers say behavior is most and least likely.
- Expect reactivity. People, including the client, may act differently when an observer is present. Giving people time to adjust to an observer, and observing across several sessions, can reduce this effect.
Definitions
- Descriptive assessment: direct observation of behavior and the antecedents and consequences that naturally surround it, without systematically changing anything.
- ABC continuous recording: during a set observation period, the observer records each occurrence of the target behavior along with selected antecedent and consequence events. Codes or checklist columns are often built from interview information so recording is fast and consistent.
- ABC narrative recording: the observer records only when the behavior of interest occurs, writing an open-ended description of what happened just before and just after it. It takes less time but captures less structure and depends heavily on observer judgment.
- Scatterplot: a grid that shows whether, or how much, behavior occurred in each time block (such as each 30 minutes) across many days. Touchette and colleagues (1985) described it as a way to spot temporal patterns linked to routines, activities, or people.
- Structured descriptive assessment: the caregiver presents a natural antecedent (such as hard work) at planned times during the usual routine, while consequences are left as they naturally occur. Use it when the antecedent you need to sample rarely happens on its own.
- Conditional probability: the likelihood that an event (such as attention) follows the behavior, given that the behavior occurred. It is most useful when you compare it with the background probability, how often that same event occurs at any time, regardless of behavior.
Examples from a session
Descriptive assessment across settings
- School: Malik, age 8, tears worksheets. His teacher uses an ABC continuous-recording checklist during a 30-minute math block. Most tearing follows "Finish this page," and the most common consequence is being sent to the hallway. His BCBA writes down "escape from math tasks" as a hypothesis to test.
- Group home: Staff mark a scatterplot for Rosa, 34, every half hour for three weeks. Property destruction clusters between 4:00 and 5:00 p.m., when staff change shifts. Her BCBA schedules ABC observations for that hour.
- Home: Theo, 3, screams during evening routines. His parent jots a short ABC narrative each time screaming occurs. Several notes mention screaming when a tablet is turned off, which shapes the next round of observation.
- Clinic: Ji-woo, 16, hits his head. His BCBA compares how often staff attention follows head hitting with how often staff talk to him at all. Attention is common either way, so she does not assume an attention function.
Common mistakes / exam traps
- Calling a correlation a function. "Attention followed 80% of outbursts" does not show that attention maintains outbursts. Adults often attend to people throughout the day, and problem behavior often draws attention no matter what its function is.
- Ignoring the background rate. A consequence that follows behavior often may follow no behavior just as often. Compare conditional and background probabilities before reading much into a pattern.
- Missing intermittent reinforcement. A maintaining consequence may occur only now and then, so it can look rare in a brief sample.
- Using a scatterplot to identify function. A scatterplot shows when behavior happens. It points you toward routines or people to examine, but it records nothing about consequences.
- Treating descriptive as indirect. Rating scales and interviews are indirect because they rely on someone's report. Descriptive assessment is direct observation.
Exam trap
When an answer choice says descriptive data "confirm," "prove," or "identify" a function, be suspicious. The safer answer treats the pattern as a hypothesis and, when appropriate, tests it by manipulating variables.
Exam trap
ABC continuous vs. ABC narrative recording: ask when the observer writes. Continuous recording scores every occurrence, with preselected codes, across a set observation period. Narrative recording is free text written only when the behavior occurs. A notebook entry after each episode is narrative, however detailed it is.
Quick check
Nadia, a BCBA, reviews four weeks of scatterplot data for Eli, 12. Elopement from class occurs almost only between 11:30 a.m. and noon on weekdays. What is the best next step?