Free · 2026 · ABA skill acquisition for the RBT exam Prompt hierarchy in ABA: every type of prompt, most-to-least and least-to-most, with a walkthrough
The prompt hierarchy is the ordered list of prompts used in ABA to help a learner respond correctly, from the most intrusive help to the least, ending with no prompt at all. A common order, from most to least intrusive, is full physical (hand-over-hand), partial physical (a light touch), model (showing the response), gestural (pointing) and verbal (a spoken hint); sources differ on whether verbal or gestural prompts are less intrusive, and the learner's plan sets the order. Prompts are used in one of two directions. Most-to-least prompting starts with the most help and fades it as the learner succeeds, which keeps errors low for new skills; least-to-most prompting gives the learner a chance first and adds help one level at a time. Every prompt is meant to be faded, so the instruction alone ends up controlling the response, and a learner who waits for a prompt has prompt dependence. Prompting with fading is task C.7 on the 3rd edition RBT Test Content Outline and task 11 of the 2026 RBT competency assessment. Below: the hierarchy with an example of each prompt, response vs stimulus prompts, the prompting strategies compared, a step-by-step walkthrough, and a free 14-question drill with answers.
The prompt hierarchy, most to least intrusive
Every example teaches the same instruction, "Touch red," so you can see how the help shrinks at each level.
- Full physicalHand-over-hand guidance through the whole responseThe RBT's hand guides the learner's hand onto the red card.
- Partial physicalA light touch or nudge at the hand, wrist, elbow or shoulderA light tap at the elbow, toward the red card.
- ModelShowing the response for the learner to copyThe RBT touches the red card, then says "Your turn."
- GesturalPointing, nodding, reaching or looking toward the answerThe RBT points at the red card.
- VerbalWords added to the instruction: a hint, a rule or the answer"Red, like an apple."
- IndependentNo prompt: the instruction alone"Touch red," and the learner touches red.
Some hierarchies add visual prompts (pictures, written words) near the bottom. Where verbal and gestural prompts sit is the part sources disagree on most: verbal prompts are often listed as the least intrusive, but they can be the hardest to fade. Follow the order in the learner's plan.
Response prompts vs stimulus prompts
Response prompts are things the instructor does to help the response happen: the verbal, gestural, model and physical prompts above. Stimulus prompts change the materials instead, making the right answer stand out, and they're faded by stimulus fading. Task C.7 names both.
| Stimulus prompt | What changes | How it's faded |
|---|---|---|
| Position | The right card sits closer to the learner | Move it back into the row, a little at a time |
| Size | The right card is bigger than the others | Shrink it to the same size |
| Color or highlight | The right word is bold or outlined | Fade the highlight until it's gone |
| Added picture | A picture of an apple sits under the word "red" | Fade the picture out |
Most-to-least, least-to-most, time delay and other prompting strategies
| Strategy | How it works | Best for |
|---|---|---|
| Most-to-least (MTL) | Start with the most help (often full physical) and move to less help as the learner succeeds at each level | New skills, and learners for whom errors are costly; keeps errors low but can slow learning |
| Least-to-most (LTM) | Give a chance to respond alone first, then add one more intrusive prompt at a time until the learner responds | Skills the learner partly knows; faster for some learners, with more errors |
| Time delay | Prompt right after the instruction at first (0-second delay), then wait before prompting: a fixed wait (constant, e.g. 3 s) or a growing one (progressive) | Giving the learner room to answer before the prompt, with few errors |
| Graduated guidance | Physical guidance that lightens as the learner moves on their own and returns if they stop | Motor skills such as dressing or handwashing |
| Errorless learning | Prompting so the learner almost never responds wrongly (MTL, 0-second delay, stimulus fading), then fading | New skills where repeated errors would be practiced |
| Stimulus fading | An exaggerated feature of the materials (position, size, color) is gradually removed | Fading stimulus prompts |
What the research says
Libby and colleagues (2008) compared the two directions while teaching children with autism to build Lego structures. Every child learned with most-to-least prompting, which produced fewer errors, but three learned faster with least-to-most. Most-to-least with a 2-second delay before each prompt was nearly as fast as least-to-most, with fewer errors. Karsten and Carr (2009) found that saving high-quality reinforcers for unprompted responses produced skill acquisition more reliably than reinforcing prompted and unprompted responses alike, a preliminary finding the authors suggest as a default.
Walk through it: least-to-most and most-to-least
Make each decision an RBT makes during a trial, and watch the ladder: the highlighted rung is the current prompt level, and the marks show what happened at each level.
The plan: least-to-most prompting for "Touch red," with a 3-second wait at each level. The order, least to most: independent, verbal, gestural, model, partial physical, full physical.
- Full physical
- Partial physical
- Model
- Gestural
- Verbal
- Independent (current level)
- Top: most intrusive. Bottom: no prompt.
Step 1 of 4 · now at: independent
You say "Touch red" and wait 3 seconds. The learner doesn't respond. What do you do next?
Prompt dependence, and how to prevent it
Prompt dependence is when a learner waits for help instead of responding to the instruction, even for skills they can do. It usually comes from prompts that stay too long, prompts nobody planned (a glance at the right card, a repeated instruction, a hand hovering nearby), or reinforcement that is just as good for prompted responses as for independent ones. The fixes are the reverse: a fading plan from the first session, fading as soon as the plan's criteria are met, watching for unplanned prompts, and, where the plan says so, saving the best reinforcers for independent responses. Reinforcing independent responses more than prompted ones is itself a form of differential reinforcement.
Prompting practice: 14 questions with answers
Name the prompt, pick the strategy, and spot prompt dependence, like the questions on the RBT exam. The reason shows after each answer.
Question 1 of 14 · 0 right so far
The RBT says "Touch red" and points at the red card. Which prompt is the point?
Prompting on the RBT exam
On the 3rd edition RBT Test Content Outline, Behavior Acquisition is 19 of the 75 scored questions. Task C.7 covers stimulus and response prompts with fading: errorless learning, least-to-most, stimulus fading and time delay. Expect scenarios that ask which prompt an RBT used, which strategy fits a learner, or what comes next in a prompting sequence.
- Response prompts are what you do (verbal, gestural, model, physical); stimulus prompts change the materials (position, size, color).
- Most-to-least starts with the most help; least-to-most starts with no help. Read which end the scenario starts from.
- A point is gestural; showing the whole response is a model.
- Constant time delay uses one fixed wait; progressive time delay grows the wait.
- Record the prompt level the learner needed. A prompted response is never scored as independent.
- Every prompt needs a plan to fade it. Unfaded prompts lead to prompt dependence.
On the 2026 competency assessment
Task 11 of the RBT Initial Competency Assessment is "Prompting: Implement prompt and prompt fading procedures," with a client or in role-play. Practice saying which prompt you're using and how you'll fade it, and recording the prompt level for each trial. Our RBT competency assessment guide has a role-play for each of the 19 tasks.
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Prompt hierarchy FAQ
What is the prompt hierarchy in ABA?
The prompt hierarchy is the ordered list of prompts used to help a learner respond correctly, from the most intrusive to the least: full physical, partial physical, model, gestural and verbal, then no prompt. It gives prompting a planned direction, so prompts can be added (least-to-most) or faded (most-to-least) one level at a time.
What are the types of prompts in ABA?
Response prompts are what the instructor does: verbal (words), gestural (pointing or looking), model (showing the response) and physical (partial or full guidance). Stimulus prompts change the materials instead: the right item's position, size or color, or an added picture. Some lists also include visual prompts such as pictures or written cues.
Is a verbal prompt more or less intrusive than a gestural prompt?
Sources differ. Many ABA hierarchies put verbal prompts as the least intrusive, but some rank them above gestures because verbal prompts can be hard to fade. Follow the order in your learner's plan; the BCBA sets it.
What is the difference between most-to-least and least-to-most prompting?
Most-to-least starts with the most help and fades it as the learner succeeds, which keeps errors low and suits new skills. Least-to-most gives the learner a chance to respond alone first, then adds more intrusive prompts one level at a time until they respond, which suits skills they partly know. In one study, most-to-least produced fewer errors while some learners learned faster with least-to-most.
What is prompt dependence?
Prompt dependence is when a learner waits for a prompt instead of responding to the instruction alone, even for skills they can do. It's prevented by planning how each prompt will be faded, fading on schedule, avoiding unplanned prompts like glancing at the answer, and often reinforcing independent responses more than prompted ones.
What is prompt fading?
Prompt fading is the gradual removal of prompts so the instruction alone controls the response. It happens by moving down the hierarchy (most-to-least), by waiting longer before prompting (time delay), or by removing stimulus prompts bit by bit (stimulus fading).
What is errorless learning?
Errorless learning arranges prompts so the learner almost never responds wrongly, using most-to-least prompting, a 0-second time delay or stimulus prompts, and then fades them. The idea is that the learner practices only the correct response.
How do you record prompted responses?
Record the level of prompt the learner needed on each trial, such as "correct with a gestural prompt". A prompted response is never scored as independent, or the data will show a skill as learned before it is.
Sources, checked October 28, 2026: BACB: RBT Test Content Outline (3rd ed.) · BACB: RBT Initial Competency Assessment (2026) · Libby, Weiss, Bancroft & Ahearn (2008): A comparison of most-to-least and least-to-most prompting, Behavior Analysis in Practice · Karsten & Carr (2009): Differential reinforcement of unprompted responding, JABA · Cooper, Heron & Heward: Applied Behavior Analysis (3rd ed., 2020). For exam study, not clinical guidance: your supervising BCBA sets the prompt order, wait times and fading criteria, and RBTs carry out the plan as written.