Reference

ABA terms and definitions

An ABA treatment plan is written in a technical vocabulary, and nobody translates it. Parents get a document containing “mand”, “S^D” and “differential reinforcement of alternative behaviour” and are asked to sign it. New technicians nod at “run a quick preference assessment” and look it up afterwards.

These are the 49 terms that actually come up, defined in one or two sentences each. For the compliance vocabulary that appears when a clinic evaluates software — BAA, PHI, covered entity — see the HIPAA glossary.

The foundations

The four words the rest of the vocabulary is built out of. Every procedure below is a way of arranging one of these.

Applied behavior analysisABA: The applied branch of the science of behaviour: the systematic use of principles derived from the experimental study of behaviour to produce meaningful change in behaviours that matter to the person and the people around them, with ongoing measurement used to establish that the intervention is what caused the change.The measurement half is not administrative garnish. An intervention that improved something without data showing it was the intervention that did so is not applied behaviour analysis; it is a hopeful guess with a good outcome.
Behaviour: Anything a person does that can be observed and measured. In behaviour analysis the term is neutral and covers speaking, walking, requesting, hitting and sitting still equally — it does not mean "misbehaviour".This is the definition that most often surprises parents, because outside the clinic "behaviours" is a euphemism for problems. Inside it, a mand is a behaviour and so is putting shoes on.
Antecedent, behaviour, consequenceABC: The three-term contingency used to describe any instance of behaviour: what happened immediately before, what the person did, and what happened immediately after. It is the basic unit of analysis and the basic format for descriptive data collection.
Stimulus: Any change in the environment that a person can detect and that may affect what they do. Antecedents and consequences are both stimuli; the label describes when it occurs relative to the behaviour, not what kind of thing it is.
Discriminative stimulusSD: A stimulus in whose presence a particular behaviour has been reinforced in the past, and which therefore makes that behaviour more likely now. In teaching, the SD is usually the instruction or the material presented at the start of a trial.Written Sᴰ in textbooks and said as "ess-dee" on the floor. Staff also say "the SD" loosely to mean the instruction itself, which is close enough for a session and wrong in an exam.
Motivating operationMO: An environmental variable that changes how effective a consequence is as a reinforcer, and correspondingly changes how likely the behaviours that produce it are. Deprivation and satiation are the everyday examples.This is the piece that explains why a program that worked at 9am fails after lunch, and why "he was just being difficult" is almost never the useful description.

Reinforcement, punishment and extinction

The consequence side of the contingency, where the words have precise technical meanings that differ sharply from their everyday ones.

Reinforcement: A consequence that makes the behaviour it followed more likely to happen again in similar circumstances. It is defined entirely by that effect: if the behaviour did not increase, whatever you delivered was not a reinforcer, however much the person appeared to enjoy it.
Positive and negative reinforcement: Positive reinforcement adds something after the behaviour; negative reinforcement removes or postpones something. Both increase the behaviour — "negative" describes the removal, not a bad outcome.Negative reinforcement being read as punishment is the single most common misunderstanding in the vocabulary, including among people who have completed training.
Punishment: A consequence that makes the behaviour it followed less likely to happen again. As with reinforcement, the term is defined by its effect on future behaviour and carries no implication about severity or intent.Punishment-based procedures are heavily restricted in practice, require specific justification and consent, and are not part of most clinics’ standard programming. The word appearing in a textbook is not evidence it is happening in a session.
Extinction: Withholding the reinforcement that has previously maintained a behaviour, so that the behaviour gradually stops being produced. It is a procedure, not an absence of one, and it only works if the maintaining reinforcer has been identified correctly.
Extinction burst: A temporary increase in the frequency, intensity or duration of a behaviour shortly after extinction begins. It is expected, it is planned for, and it is the point at which an unsupported extinction plan usually gets abandoned at home.Worth naming explicitly to parents before a plan starts. A burst that nobody warned them about reads as the program making things worse.
Schedules of reinforcement: The rule describing which instances of a behaviour produce reinforcement. Continuous reinforcement follows every instance; intermittent schedules follow some, and are defined by whether the requirement is a number of responses (ratio) or a period of time (interval), and whether that requirement is fixed or variable.The four intermittent schedules are fixed ratio (FR), variable ratio (VR), fixed interval (FI) and variable interval (VI). Teaching typically starts near-continuous and thins toward variable schedules, because variable schedules produce behaviour that persists.
Differential reinforcement: Reinforcing one class of behaviour while withholding reinforcement for another. The common variants reinforce an alternative behaviour that serves the same function (DRA), an incompatible behaviour (DRI), or the absence of the target behaviour for a period (DRO).

Teaching procedures

How a target gets taught. Most of a session is one of these, and most parent questions about "what are you actually doing" are answered here.

Discrete trial trainingDTT: Teaching arranged as a series of short, clearly bounded trials, each with an instruction, an opportunity to respond, a consequence and a brief pause before the next one. It suits skills that need many repetitions and produces clean trial-by-trial data.
Natural environment teachingNET: Teaching embedded in ordinary activity and led by what the learner is currently interested in, using naturally occurring opportunities and naturally related consequences rather than a prearranged trial sequence.Also called natural environment training, incidental teaching or naturalistic teaching depending on the clinic and the era of the person’s training. Most programmes run NET and DTT together rather than choosing.
Prompt: Help added to make a correct response more likely, over and above the instruction itself. Prompts are usually ranked from most to least intrusive — physical, model, gestural, positional, verbal — and the ranking is what makes a fading plan possible.
Prompt fading: Systematically reducing the help provided across trials so the response comes under the control of the natural instruction rather than the prompt. Without a fading plan, a skill that looks mastered in session is a skill that only occurs when an adult is prompting it.
Errorless learning: Prompting immediately and at sufficient strength that the learner responds correctly from the first trial, then fading that prompt, rather than allowing errors and correcting them. Used where repeated errors would slow acquisition or make the task aversive.
Shaping: Reinforcing successively closer approximations to a target behaviour that the learner cannot yet perform. Each step is reinforced until it is reliable, then the criterion moves.
Task analysis and chaining: Task analysis breaks a complex skill into its component steps in order. Chaining teaches those steps as a sequence — forward from the first step, backward from the last, or as a total task with prompting throughout.
Pairing: Deliberately associating a person, setting or material with things the learner values, so that the person or place itself becomes something worth approaching. It is what the first sessions with a new technician are mostly for.
Generalisation: A skill occurring outside the conditions it was taught in — with different people, in different settings, with different materials, and without prompts. It is planned for from the start rather than hoped for at the end.This is the single most common reason a parent and a clinic disagree about whether something is working. The skill is real and the data are honest; it just has not generalised to the kitchen yet.
Maintenance: A skill continuing to occur after teaching has stopped and reinforcement has thinned. Mastered targets are moved into periodic maintenance checks rather than dropped, because skills that are never revisited quietly disappear.

Language and verbal behaviour

Behaviour analysis classifies language by what the speaking does rather than by what the words mean, which is why these labels look nothing like grammar.

Mand: A request. The learner asks for something they currently want, and the consequence that maintains it is getting that specific thing.Mands are usually the first target in an early programme, because a child who can ask has an alternative to the behaviour that used to get the same result.
Tact: Naming or commenting on something present — labelling a picture, pointing out a dog — where the consequence is social rather than getting the item itself.
Echoic: Repeating what was just said, where the response matches the model. It is a teaching tool as much as a target: much of early vocal work runs through an echoic prompt.
Intraverbal: Responding to someone else’s words with words that are not a repetition of them — answering a question, filling in a blank, holding a conversation. It is the class most conversation goals live in.
Listener responding: Following what somebody else says: touching the named item, carrying out an instruction. Sometimes still called receptive language, which is the older term.
Augmentative and alternative communicationAAC: Any communication method used alongside or instead of speech, including sign, picture exchange and speech-generating devices. Introducing AAC does not reduce the likelihood of vocal speech developing, which is the question families ask first.

Assessment and planning

What happens before a target is written, and the documents that come out of it. This is the vocabulary of the paperwork a family is handed.

Functional behaviour assessmentFBA: The process of working out what a behaviour accomplishes for the person — what maintains it — using interviews, direct observation and record review. The conclusion is a hypothesis about function, and it determines what the intervention can reasonably be.Functions are conventionally grouped as access to something tangible, attention, escape from a demand, and automatic or sensory reinforcement. A behaviour can serve more than one.
Functional analysisFA: The experimental part of a functional assessment: conditions are arranged and systematically varied to test directly which consequence maintains the behaviour, rather than inferring it from observation alone.Often used interchangeably with FBA in casual conversation. They are not the same thing — an FA is one method within an FBA, and it is not always indicated.
Preference and reinforcer assessment: A structured way of finding out what a learner will actually work for. A preference assessment identifies what they choose; a reinforcer assessment confirms that access to it increases behaviour.
Skills assessment: A criterion-referenced inventory of what a learner can currently do, used to select and sequence targets. The VB-MAPP and the ABLLS-R are the two most commonly used in early intervention.
Baseline: Measurement of the behaviour before intervention begins, used as the comparison against which any later change is judged. Without it there is no basis for saying a programme worked.
Behaviour intervention planBIP: The written plan for a specific behaviour: the operational definition, the hypothesised function, the antecedent strategies, what to teach instead, how to respond when it occurs, and how it will be measured.Sometimes called a behaviour support plan or behaviour plan. Whatever it is titled, everyone who works with the child is supposed to be running the same one, which is what makes handoff a clinical event rather than an administrative one.
Treatment plan: The overall clinical document for a client: assessment findings, goals, recommended service hours, and the criteria for progress. It is usually what the funder authorises against and what gets reviewed every six months.
Mastery criteria: The standard a target has to meet before it counts as learned — typically a percentage of correct, unprompted responses across a number of consecutive sessions and, ideally, more than one person and setting.
Operational definition: A description of a behaviour precise enough that two people observing independently would agree on whether it happened. Writing one is the step that makes the data mean anything.

Measurement and data

What gets recorded during a session, and why a technician is holding a clicker or a tablet.

Frequency and rate: Frequency is a count of how many times a behaviour occurred. Rate is that count divided by the time observed, which is what makes two sessions of different lengths comparable.
Duration and latency: Duration is how long a behaviour lasts. Latency is how long it takes to start after the instruction or event. Both are used where a count would miss the point — a tantrum is better described by how long it went on than by how many there were.
Interval recording: Sampling rather than counting continuously: the observation is divided into intervals, and each is scored for whether the behaviour occurred throughout it (whole interval), at any point in it (partial interval), or at the moment it ended (momentary time sampling).These produce estimates, and the choice of method biases the estimate in a known direction. Partial interval tends to overestimate, whole interval to underestimate.
Trial-by-trial data: Recording the outcome of each individual teaching trial — correct, incorrect, or the level of prompt needed — rather than a single summary judgement for the session. It is what makes a prompt-fading decision defensible.
Interobserver agreementIOA: The extent to which two independent observers recording the same behaviour at the same time produce the same data. It is the check on whether an operational definition is actually working.
Session note: The clinical record of a session: what was run, what the data showed, what happened, and any clinically relevant event. It is written for the record, for supervision and for the funder, and it is not the same document as the update a parent should receive.

People and credentials

Who is in the room, who supervises whom, and what the letters after a name mean.

Board Certified Behavior AnalystBCBA: A graduate-level certification issued by the Behavior Analyst Certification Board. A BCBA conducts assessments, designs and revises programmes, and supervises the staff delivering them.
Board Certified Assistant Behavior AnalystBCaBA: An undergraduate-level BACB certification. A BCaBA delivers and supports behaviour-analytic services under the supervision of a BCBA and may in turn supervise technicians.
Registered Behavior TechnicianRBT: A paraprofessional BACB certification. An RBT implements the programme written by the supervising analyst and collects the data, working under ongoing supervision rather than independently.The RBT is the person a parent actually sees every day, and the person who knows how the afternoon went. That is the whole reason parent communication is a technician-facing problem rather than an administrative one.
Supervision: The structured oversight a certificant provides to the staff delivering services, including direct observation of sessions, feedback and programme revision. It is a certification requirement with minimum contact obligations, not an optional management practice.
Caregiver training: Teaching the people who live with the child to run the relevant strategies themselves. It is usually a billable, goal-bearing part of the treatment plan rather than a courtesy, because a skill that only occurs in clinic has not generalised.Sometimes called parent training or parent education. It is a different thing from parent communication: training is scheduled, clinical and periodic; communication is daily and continuous, and one does not substitute for the other.

Why a parent-facing update is not written in this language.

Everything above is the correct vocabulary for a clinical record, and a session note should use it. A parent update should not. The same afternoon can be described as “three mands at partial physical prompt, DRA in effect, two instances of the target behaviour” or as “he asked for the bubbles three times today, which is new” — and the second is not a simplification of the first, it is the part that means something to the person receiving it.

Which is why translating clinical notes into parent updates by hand does not scale, and why asking technicians to write both is how the second one stops happening by Thursday. The practical version of this problem is covered in what belongs in a daily note for parents and in what a session note is for.

Questions people ask about ABA terminology.

What is the ABA definition of behaviour?

Anything a person does that can be observed and measured. The term is deliberately neutral: speaking, requesting, walking, hitting and sitting still are all behaviour. This is the definition that most often surprises families, because outside a clinic "behaviours" is usually a euphemism for problems, whereas inside one a request is a behaviour and so is putting shoes on.

What does ABA stand for?

Applied behavior analysis. It is the applied branch of the science of behaviour: principles established in experimental research, used systematically to change behaviour that matters to the person, with measurement throughout to establish that the intervention is what produced the change. The abbreviation is also used loosely to mean the service itself — "she is in ABA" — which is how it appears on most insurance paperwork.

What is the difference between an FBA and a functional analysis?

A functional behaviour assessment is the whole process of working out what a behaviour accomplishes for the person, using interviews, direct observation and record review. A functional analysis is one method within it, in which conditions are experimentally arranged and varied to test the hypothesis directly. The terms get used interchangeably in conversation, but an FA is not always indicated and an FBA does not always include one.

What are the four functions of behaviour?

Conventionally: access to something tangible, attention, escape from a demand, and automatic or sensory reinforcement. They describe what the behaviour produces for the person rather than why they are doing it in any intentional sense, and a single behaviour can serve more than one function at different times.

What is negative reinforcement in ABA?

Removing or postponing something after a behaviour, with the result that the behaviour becomes more likely. "Negative" refers to the removal, not to anything undesirable, and negative reinforcement increases behaviour just as positive reinforcement does. Reading it as a synonym for punishment is the commonest error in the whole vocabulary.

What are the schedules of reinforcement?

The rule that determines which instances of a behaviour produce reinforcement. Continuous reinforcement follows every instance. Intermittent schedules follow some, and are named by whether the requirement is a number of responses (ratio) or an amount of time (interval), and whether it is fixed or variable: FR, VR, FI and VI. Teaching usually starts near-continuous and thins toward variable schedules, because behaviour maintained on a variable schedule persists.

What is the difference between DTT and NET?

Discrete trial training arranges teaching as a series of short, clearly bounded trials with an instruction, a response and a consequence. Natural environment teaching embeds the same targets in ordinary activity, led by what the learner is currently interested in. They are not competing philosophies in most clinics — a session usually contains both, chosen per target.

What do RBT, BCaBA and BCBA mean?

They are the three Behavior Analyst Certification Board credentials. A Registered Behavior Technician is a paraprofessional who implements the programme and collects the data under supervision. A Board Certified Assistant Behavior Analyst holds an undergraduate-level certification and works under a BCBA. A Board Certified Behavior Analyst holds a graduate-level certification, conducts assessments, designs the programme and supervises the staff running it.

Is there an ABA terms cheat sheet or PDF?

This page is intended to be that, without the download: it is grouped the way the vocabulary is actually used, it can be searched with a browser find, and it does not go out of date on somebody’s hard drive. If your clinic wants a printed version for a new-hire pack, print this page — it is laid out to survive it.

HIPAA glossary for ABA clinics

ABA session notes: what goes in one

ABA daily notes for parents: what to include

What ABA therapy for children involves

Sources

Every claim about another product on this page is a quote from that product’s own documentation, linked below with the date we last read it there. Vendors revise these pages. If you find one of these out of date, tell us and we will correct it.

[1] Behavior Analyst Certification Board — BCBA Test Content Outline (6th ed.) · checked August 31, 2026

We build the parent-facing half of this.

Cliqit is not a data collection system and it does not write your session notes. It is the channel that turns what staff already logged into something a family can read.

Book a 15-min call Or email us a question