Every graph, definition, and intervention starts with one question: what exactly are we counting? These three terms answer it.
Why it matters
If you group responses by how they look instead of what they do, your assessment and treatment can go wrong. A child who hits, screams, and drops to the floor might be doing three different things, or one thing in three forms. If all three end a hard task, a plan that targets only hitting may leave screaming and dropping in place, or even make them more frequent.
In practice vignettes, the questions are usually three: does this count as behavior, is this one response or a class, and do these responses belong together?
Key ideas
- Behavior is what an organism does. In behavior analysis, behavior is the part of an organism's interaction with its environment that involves movement of some part of the organism and that changes the environment in some measurable way. It is something a person does, not a state, a label, or the absence of action.
- The dead man's test is a quick screen. If a dead person could "do" it (stay quiet, not hit, sit still), it is not behavior. Rewrite the target as something the person does instead, such as "raises a hand" or "keeps hands on the desk while writing."
- A response is one instance. The word behavior often refers to a larger class or a general type, like "requesting." A response is one specific occurrence of it that you could count, time, and graph.
- Responses can be described by form or by function.
- Topography is the physical form: what the response looks like, how it moves, its shape.
- Function is the effect the response has on the environment, such as producing attention, ending a demand, or getting an item.
- A response class is a group of responses. Behavior analysts most often group responses by function: responses that may look very different but produce the same effect on the environment. Responses can also be grouped by shared topography, but the functional grouping is the one that guides treatment.
- Reinforcement works on classes, not single responses. A response that already happened cannot be changed. When a consequence follows a response, it changes the future likelihood of similar responses, that is, of the class.
- An easier member can crowd out the others. When a new response produces the same reinforcer faster or with less effort, the other members of its class tend to decrease, even if they still produce that reinforcer.
- Same form, different function, and the reverse. Two responses with identical topography can serve different functions, and very different topographies can serve the same function.
Definitions
- Behavior: the activity of a living organism; the part of its interaction with the environment that involves movement. A person's full set of behaviors makes up their repertoire.
- Response: a single, specific instance of behavior that can be observed and measured.
- Topography: the physical form or shape of a response.
- Response class: a group of responses that produce the same effect on the environment, even when their topographies differ.
- Repertoire: all the behaviors a person can do, or the set of skills relevant to a particular situation.
Examples from a session
Sorting responses into classes
- One class, three forms (clinic): When a writing task appears, Theo, age 8, says "I'm tired," pushes the paper away, or puts his head on the table. Each one leads his therapist to pause the task. These responses look different but share a function, so they belong to one response class maintained by escape.
- One form, two functions (school): Two middle schoolers both slam their books on the desk. For Rosa, it reliably gets her teacher's attention. For Malik, it gets him sent out of a group activity he dislikes. Same topography, different functional response classes, and different interventions.
- Counting responses (home): A parent tallies each time Ayesha, age 4, says "more" at snack. Each "more" is one response; the tally is a count of responses in the class "requesting more food."
- Adult setting: At his job site, Daniel, 32, asks for help by signing HELP, tapping his coworker's shoulder, or saying "Can you show me?" All three get assistance, so the support plan treats them as one class and strengthens the form that works best for him in that setting.
- Non-example (near miss): A goal reads "Kofi, age 5, will not grab food at snack." Not grabbing is not a response or a class; it fails the dead man's test. Rewrite it as something he does, such as saying "more."
When you write an operational definition, say whether you are measuring one topography or a whole functional class. Many definitions of problem behavior list several forms because they share a function.
Common mistakes / exam traps
- Writing non-behavior as a target. "Will be calm" fails the dead man's test. Describe an action instead.
- Treating one response as the class. One hand raise is a response. "Hand raising" across the day is behavior you might define as a class.
- Confusing a response class with a repertoire. A repertoire is everything a person can do; a response class is a set of responses that share an effect.
Exam trap
Different forms vs. different classes. When a stem lists several different-looking behaviors, ask what each one produces. If they all produce the same effect, they are one response class, not several separate behaviors, and extinguishing one form may make the others increase.
Exam trap
Same topography vs. same function. Two people who hit, or two students who slam books, do not share a functional response class just because the responses look alike. The discriminating feature is the maintaining consequence: hitting maintained by attention and hitting maintained by escape are different functional classes and call for different interventions.
Quick check
At home, Nia, age 6, gets a parent to come over by calling 'Mom!', by tugging on a sleeve, or by banging a cup on the table. The parent comes over after each one. How are these responses best described?