Discrimination training is an essential behavioral technique in Applied Behavior Analysis (ABA) that teaches individuals to respond differently to different stimuli. The goal is to help learners identify, differentiate, and respond appropriately to specific cues in their environment.
This blog will explore discriminative stimuli (SDs), S-deltas, stimulus control, and stimulus discrimination, along with strategies for effectively implementing discrimination training.
What is Discrimination Training?
Discrimination training teaches individuals when to engage in a behavior and when not to, based on the presence or absence of specific environmental cues.
How Does Discrimination Training Work?
- A discriminative stimulus (SD) is presented, signaling that reinforcement is available for a correct response.
- The learner responds correctly by engaging in the desired behavior.
- Reinforcement follows, increasing the likelihood of future occurrence.
- An S-delta (incorrect stimulus) is presented, and if the learner responds incorrectly, reinforcement is not provided.
Example: Teaching Colors
- SD: A red car appears, and the instructor asks, “What color is this?”
- Correct Response: The learner says, “Red.”
- Reinforcement: The instructor provides praise or a reward.
- S-delta: A green car appears, but the instructor does not reinforce if the learner says, “Red.”
Over time, the learner only says “Red” when a red car is present and not when a green car is present. This process helps individuals discriminate between different stimuli, strengthening their ability to make appropriate responses in real-world situations.
Key Components of Discrimination Training
1. Discriminative Stimulus (SD)
A discriminative stimulus (SD) is a signal that reinforcement is available if the correct behavior occurs.
Examples of SDs:
- A teacher saying, “Raise your hand” signals that speaking will be reinforced if done after raising a hand.
- A green traffic light signals that driving forward is appropriate and will not be punished.
- A dog hearing a can opener associates the sound with food availability.
The SD sets the occasion for a specific behavior by signaling that reinforcement is available.
2. S-Delta
An S-delta is the opposite of an SD—it signals that reinforcement is not available for a response.
Examples of S-deltas:
- If a child yells in class without raising their hand, the teacher ignores the behavior (no reinforcement).
- A vending machine that is out of order serves as an S-delta for inserting money, as reinforcement (receiving a snack) will not occur.
- A stranger not reacting to a dog’s barking teaches the dog that barking at unfamiliar people does not result in attention.
Using S-deltas effectively ensures that learners understand when not to respond, strengthening their ability to discriminate between different stimuli.
Stimulus Control and Transfer Procedures
What is Stimulus Control?
Stimulus control occurs when a behavior is reliably triggered by the correct discriminative stimulus (SD) and not by incorrect stimuli (S-deltas).
A behavior is under stimulus control when:
- The individual only responds to the correct SD.
- The response is not performed in the presence of an S-delta.
Example:
A child only says “Mom” when their mother enters the room and not when their father enters.
Stimulus Control Transfer Procedures
Once stimulus control is established, it may need to be transferred to another stimulus for generalization.
Steps for Stimulus Control Transfer:
- Use prompts (gestural, verbal, physical) to elicit the correct response.
- Gradually fade prompts to encourage independent responding.
- Reinforce correct responses to strengthen learning.
- Ensure generalization by practicing in different environments.
Example: Teaching “Sit” to a Dog
- Initially, the trainer says, “Sit” while giving a hand signal.
- Over time, the trainer fades the hand signal, so the dog sits only when hearing the word “Sit.”
- This ensures that the verbal cue alone gains stimulus control over the behavior.
Stimulus Discrimination vs. Stimulus Generalization
Stimulus Discrimination
Stimulus discrimination occurs when an individual learns to respond differently to similar stimuli based on reinforcement history.
Example:
A child learns to say “Red” only when seeing a red car and not when seeing an orange or green car.
Discrimination helps individuals make precise distinctions, ensuring that behaviors are appropriately applied.
Stimulus Generalization
Stimulus generalization occurs when an individual applies a learned response to similar stimuli.
Example:
A child learns to say “Dog” when seeing a Labrador. If they later call a Golden Retriever “Dog” as well, generalization has occurred.
While discrimination ensures specific responses to specific stimuli, generalization ensures that skills are applied flexibly across environments and situations.
How to Implement Discrimination Training Effectively
- Start with Clear SDs and S-Deltas
Ensure the individual understands what is expected by providing clear, distinct stimuli. Example: Teaching an Individual to Say “Apple”- Present an apple (SD) and reinforce the correct response.
- Present a banana (S-delta) and do not reinforce an incorrect response.
- Reinforce Correct Responses Immediately
Provide positive reinforcement (praise, tokens, preferred items) immediately following a correct response to increase learning. - Use Prompts and Fade Them Gradually
If a learner struggles, use verbal, gestural, or physical prompts to guide the correct response.
Slowly fade prompts to encourage independence. - Mix in Mastered Skills (Interleaved Practice)
Incorporate previously mastered skills to keep the learner engaged and maintain retention. - Ensure Generalization
- Vary stimuli (different shades of red for color discrimination).
- Teach in multiple environments to encourage real-world application.
- Use different instructors to strengthen learning across contexts.
Final Thoughts
Discrimination training is essential for teaching individuals how to differentiate between stimuli and respond appropriately. By using SDs, S-deltas, reinforcement, and stimulus control techniques, learners develop skills that help them navigate real-world environments effectively.
Key Takeaways:
- SDs signal reinforcement availability—correct responses lead to reinforcement.
- S-deltas signal no reinforcement—incorrect responses are not reinforced.
- Stimulus control ensures behaviors occur only in the presence of the correct cues.
- Discrimination training helps learners differentiate between similar stimuli.
- Generalization ensures learned behaviors apply in different settings.
By implementing effective discrimination training strategies, we can help learners build independence, communication skills, and adaptive behaviors.
What strategies have you used for teaching discrimination? Share your insights in the comments!