RBT

Data Collection and Graphing is Domain A of the RBT Test Content Outline and carries 13 of the 75 scored questions (17%). Applied behavior analysis is a data-based science: every decision a supervisor makes about a client's program, whether to continue, change, or end an intervention, depends on the data an RBT collects. This domain tests whether you can define behavior precisely, select and carry out the right measurement procedure, calculate and summarize the results, enter data and update graphs, read trends, and recognize what makes data unreliable.

In ABA, behavior is anything a person does that can be observed and measured. A quick check is the dead man's test: if a dead man could do it, it is not behavior. "Sitting still," "not hitting," and "being quiet" fail the test, so they are not usable targets. Restate them as something the person does: "sitting with hands in lap," "keeping hands on the table," or "speaking at conversational volume."

Behavior has three measurable properties, called dimensional quantities, and every measurement procedure in this section captures one of them.

Dimension	Meaning	MeasuresItProduces
Repeatability	Behaviorcanoccuragainandagain soitcanbe ,	Count rate(frequency) celeration , ,
	counted
Temporalextent	Everyresponselastssomeamountoftime	Duration
Temporallocus	Everyresponseoccursatapointintimerelative	Latency interresponsetime(IRT) ,
	tootherevents

An operational definition describes a behavior in observable, measurable terms so precisely that two people watching the same session would score it the same way. A good definition is objective (only observable features, no feelings or intentions), clear (readable and unambiguous), and complete (it states what counts and what does not, the boundaries of the behavior). Definitions can be topography-based, describing what the behavior looks like, or function-based, describing its effect on the environment.

"Marcus gets angry and hurts other people."

"Aggression: any instance of Marcus striking another person with an open or closed hand, kicking, biting, or scratching, from a distance of less than arm's length. Accidental contact during play is not scored."

Measurement must be valid, meaning it measures the behavior of interest in a way that is relevant to the decision being made, and reliable, meaning it produces the same result each time the same behavior is measured. A definition of aggression that also scores clapping lacks validity; two observers who record very different counts during the same session indicate a reliability problem.

RBTs also describe the environment objectively: the setting, people present, materials, instructions given, and events immediately before and after a behavior. "The room was chaotic" is an opinion; "four children and two adults were in the room, and a fire drill sounded at 10:15" is a description.

When a question asks for the best operational definition, eliminate any choice that names an internal state (angry, frustrated, bored, wants attention) or a label (tantrum, meltdown) without describing the actual movements or sounds.