Discrimination Training in ABA: Techniques and Mastery Signs

A learner who can't distinguish "sit" from "stand," or a stop sign from a stop light, has a hard time with any instruction that follows. Discrimination training in Applied Behavior Analysis (ABA) teaches this type of skill, and it shows up in nearly every treatment plan.

This guide walks you through the principles that Board Certified Behavior Analysts (BCBAs) rely on to structure discrimination training. By the end, you'll understand how to tell simple and conditional discrimination apart, as well as the stimuli involved and which techniques help move a learner forward.

What is discrimination training in ABA?

Discrimination training means teaching an ABA learner to respond one way to one stimulus and a different way to another stimulus, based on which response gets reinforced.

Every discrimination has two parts: the discriminative stimulus (SD), which signals that a specific response earns reinforcement, and the S-delta, which signals that it won't.

For example, a learner working on receptive labels might be instructed, "Touch the cup," when a cup and a shoe sit on the table. Touching the cup (the SD) earns reinforcement. Touching the shoe (the S-delta) doesn't. Over repeated trials, the learner's response starts to reliably involve the cup, not the shoe.

Why discrimination training is important in ABA

Discrimination training is important in ABA because nearly every other skill, from labeling objects to following multi-step directions, depends on a learner first telling relevant stimuli apart.

When this hasn't been established, learners can end up responding the same way regardless of what's in front of them, which can slow down programs that come after. This is partly why discrimination is often assessed across a wide range of ages and skill levels in ABA practice.

Also, teaching learners to distinguish between cues signaling that reinforcement is available and cues signaling that it isn't is linked to sustained reductions in challenging behavior.

It helps a learner rely on the more appropriate response in functional communication training, for example. A learner who can tell a "break" card from a "keep working" card has less reason to act out just to understand which one applies.

Types of discrimination training in ABA

In ABA, training breaks down discrimination into two types: simple and conditional.

Conditional discrimination asks more of the learner, since the correct answer depends on a sample they have to attend to first, not a fixed stimulus.

Some learners need more specialized teaching procedures. Researchers have found that prompting learners to verbally repeat the sample stimulus before choosing the answer helped young children with autism and impaired listening skills master new conditional discriminations.

How BCBAs teach discrimination skills

BCBAs teach discrimination skills using a mix of errorless learning, stimulus fading, and prompting, selecting the approach based on broader assessments of each learner, as well as the specific skill.

Errorless learning

Errorless learning keeps early trials nearly impossible to get wrong, usually by prompting the correct response heavily until accuracy is high.

A review of errorless learning procedures found that this approach improved discrimination skills for most participants with intellectual and developmental disabilities.

Stimulus and prompt fading

Stimulus fading gradually removes built-in cues, like size, color, or position, until the learner responds to the natural stimulus alone.

Prompt fading works alongside this, gradually removing support as accuracy improves, so the learner doesn’t come to depend on clinical support.

Managing stimulus disparity

Some discriminations are harder to teach, and stimulus disparity is one common reason.

Disparity refers to how physically different the SD and S-delta are. For instance, low-disparity symbols, like two similar letters, typically take longer to master than high-disparity ones, like a circle and a triangle.

Starting with a bigger difference between stimuli, then narrowing it as the learner improves, is one way clinicians make discrimination training more efficient.

How discrimination skills generalize in ABA

Discrimination skills generalize when learners can apply them to new people, places, and materials, especially in their daily life.

Practicing with only one set of training materials or Registered Behavior Technicians (RBTs) can mean the learner only discriminates in their familiar clinical setting. Using multiple examples of a target skill across different people and settings is typically linked to better generalization.

Manage discrimination training with Passage Health

Discrimination training only works if data on SD and S-delta responses gets captured accurately. For busy RBTs running discrimination trials minute by minute, that data can be easier to approximate than to record consistently.

Our Passage Health platform and mobile app are built to keep ABA data accurate without adding extra work for your team. Clinical data, scheduling, and billing live in the same system, so there’s no exporting or reentering information across separate tools.

Here's what that looks like for a practice managing discrimination programs:

• Log responses as they happen: RBTs enter session data directly on the app, which automatically syncs to the platform. 
• Keep timing consistent: Programmable timers can start when a session begins and keep rate, interval, and duration targets on track. 
• Watch programs progress: Automated graphing makes it easy to tell when a learner may be ready to move from simple to conditional discriminations.
• Spend more time reviewing: Integration with Frontera AI means first drafts of documents are created from session notes. 
• Adjust schedules from the field: Filter color-coded calendars by care team, billing code, and certification to simplify reassignments. See a full team or one staff member’s day at a glance, and create and edit events right in the mobile app.
• Move from session to claim faster: Claims generate directly from session data, and expired funding sources are filtered out.
• Track performance across your practice: Clinical directors get a live view of where programs are working and where caseloads need to change.
• Manage referrals without spreadsheets: Our Client Intake feature keeps prospective clients’ information organized and tracked, from first contact through conversion.

Every new practice gets 1:1 onboarding and dedicated support. The platform stays intuitive, even as we add new features every quarter, based on client feedback.

Book a demo to see how Passage Health supports discrimination training in real ABA sessions.

Frequently asked questions

What does discrimination training mean in ABA therapy?

Discrimination training in ABA therapy means teaching a learner to give a different response, depending on the stimulus in front of them. Correct responses earn reinforcement, while incorrect responses don't.

What's the difference between simple and conditional discrimination?

The main difference between simple and conditional discrimination is how the correct response is determined. With simple discrimination, the correct response stays the same regardless of context, while conditional discrimination requires the learner to reassess the sample presented each trial, like matching a picture to a spoken label that keeps changing.

How do you know when a learner has mastered a discrimination?

A learner has mastered a discrimination when they respond correctly and consistently across sessions without needing a prompt. Mastery also means that the skill holds up with new materials, people, and settings.

Why is discrimination training a core part of ABA treatment?

Discrimination training is a core part of ABA treatment because it lays the groundwork many other skills build on. Following directions, learning language, and staying safe all rely on being able to correctly tell stimuli apart.

References

Erhard, P., Falcomata, T. S., Oshinski, M., et al. (2024). The effects of multiple-exemplar training on generalization of social skills with adolescents and young adults with autism: A systematic review. Review Journal of Autism and Developmental Disorders, 11, 66–85. https://doi.org/10.1007/s40489-022-00328-4 

Fisher, W. W., Retzlaff, B. J., Akers, J. S., et al. (2019). Establishing initial auditory-visual conditional discriminations and emergence of initial tacts in young children with autism spectrum disorder. Journal of Applied Behavior Analysis, 52(4), 1089–1106. https://doi.org/10.1002/jaba.586 

Halbur, M. E., Caldwell, R. K., & Kodak, T. (2021). Stimulus control research and practice: Considerations of stimulus disparity and salience for discrimination training. Behavior Analysis in Practice, 14(1), 272–282. https://doi.org/10.1007/s40617-020-00509-9 

Kranak, M. P., & Brown, K. R. (2023). Updated recommendations for reinforcement schedule thinning following functional communication training. Behavior Analysis in Practice, 17(1), 87–106. https://doi.org/10.1007/s40617-023-00863-4 

Markham, V. A., Giles, A. F., Roderique-Davies, G., et al. (2020). Applications of within-stimulus errorless learning methods for teaching discrimination skills to individuals with intellectual and developmental disabilities: A systematic review. Research in Developmental Disabilities, 97, Article 103521. https://doi.org/10.1016/j.ridd.2019.103521