Discrete-trial teaching (DTT) is one of the most common ways RBTs teach new skills. It breaks a skill into small, teachable units and practices each one in short, repeated learning opportunities called trials. This lesson walks through what a single trial looks like and how to run trials smoothly and consistently.
Why it matters
DTT gives a learner many clear practice opportunities in a short time, and each one ends with immediate feedback. That makes it useful for skills like identifying pictures, imitating actions, answering questions, or following one-step instructions. Because every trial is scored, your supervisor can see exactly how a skill is progressing.
DTT only works when it is run the way the program describes. Small slips, like repeating an instruction, delaying the reinforcer, or always putting the correct card in the same spot, can teach the learner something other than the target skill. On the exam, expect scenarios where you name a part of the trial or spot what the RBT should have done differently.
Key ideas
- "Discrete" means each trial has a clear beginning and end. A trial starts when you give the instruction and ends after the consequence. A short pause separates it from the next trial.
- Every trial follows the same parts, in the same order:
- The instruction or cue (the discriminative stimulus, or SD).
- A prompt, only if the program calls for one.
- The learner's response.
- The consequence: reinforcement for a correct response, or the program's error-correction procedure for an incorrect one.
- The intertrial interval (ITI): a brief pause before the next trial.
- Set up before you start. Have materials ready, check what the learner wants to work for, and make sure the learner is attending before you give the first instruction.
- Give the instruction once, clearly. Use the wording the program specifies, then wait for a response or follow the prompting plan. Do not stack repeats.
- Reinforce immediately. Deliver praise and the reinforcer right after a correct response, then record the trial during the ITI.
- Arrange the trials the way the program says. Some programs use massed trials; others intersperse mastered targets among new ones to keep momentum and success high.
- Follow the written plan. Prompt types, error correction, and mastery criteria come from your supervisor. If something is not working, collect your data and raise it with your supervisor rather than changing the procedure on your own.
Definitions
- Discrete-trial teaching (DTT): an adult-led teaching method that presents a skill in brief, repeated trials, each with a distinct start and finish.
- Discriminative stimulus (SD): in DTT, the instruction or cue that signals reinforcement is available for the target response, such as "Touch dog" with three pictures on the table.
- Prompt: extra help given with or right after the SD, before the response, to make a correct response more likely (for example, pointing to the correct picture).
- Consequence: what happens right after the response. Correct responses earn reinforcement; incorrect responses get the planned error correction.
- Intertrial interval (ITI): the brief pause between the end of one trial and the start of the next, often just a few seconds. You use it to record data and reset materials.
- Massed trials: the same target presented several times in a row.
- Interspersed trials (interspersal): already-mastered targets mixed in among new targets.
Examples from a session
One trial with Priya, age 6, at a clinic table
- Setup: Priya chooses bubbles as her reinforcer. You place pictures of a cat, a car, and a ball in front of her and wait until she looks at you.
- SD: "Touch cat."
- Prompt: None needed on this trial; the program says to prompt only after a 3-second wait.
- Response: Priya touches the cat.
- Consequence: Right away you say, "Yes, that's the cat!" and blow bubbles for a few seconds.
- ITI: You mark a plus for an independent correct response, rotate the card positions, and begin the next trial.
The same structure works in other settings. At home, an RBT might run imitation trials with a 3-year-old on the living room floor ("Do this" while clapping). At school, an RBT might run sight-word trials with a 10-year-old at a desk. The setting changes; the parts of the trial do not.
Common mistakes / exam traps
- Repeating the SD. "Touch cat... touch cat... Priya, touch cat!" can teach the learner to wait for the third request. Give it once, then follow the prompt plan.
- Accidental cues. Glancing at the correct card or always placing it in the same position lets the learner answer from your eyes or the location instead of the picture. Rotate positions across trials.
- Delayed reinforcement. Writing data first and reinforcing 10 seconds later weakens the link between the response and the reinforcer.
- Long, unplanned pauses. Stretching the ITI with chatting or searching for materials slows the pace and invites disengagement.
- Scoring prompted responses as independent. If you helped, record it as prompted, using the codes on your data sheet.
- Treating DTT as "table time only." DTT is defined by its structure, not its location. It can happen on the floor, at a desk, or in a kitchen.
Exam trap
A prompt comes before the response; the consequence comes after it. If the help happens before the learner responds, it is a prompt, even when it is given at the same time as the instruction.
Exam trap
The SD starts a trial, so a response that comes before the SD is not a trial response. If the learner touches a card before you give the instruction, do not reinforce or score it: reset, gain attention, then give the SD.
Quick check
During a color program, an RBT tells Malik to touch the red one while tapping the red block. Malik touches the red block, and the RBT praises him and hands over a sticker. What is the tap on the red block?