RBT Discrete Trial Training 2 — Questions and Answers

Question 1: In a discrete trial, what is the function of the discriminative stimulus (SD)?

It follows the response and signals that reinforcement is available
It precedes the response and signals that the correct response will produce reinforcement (Correct answer)
It provides the consequence for an incorrect response
It is the pause between two consecutive trials

Correct answer: It precedes the response and signals that the correct response will produce reinforcement

The discriminative stimulus (SD) signals the availability of reinforcement — it precedes the response and indicates that a specific behavior will be reinforced in that context. Responding to the SD is what is taught in discrete trial training.

The discriminative stimulus (SD) is a stimulus in the presence of which a specific response has been reinforced in the past. In discrete trial teaching, the SD is what the instructor presents to occasion the target response — it is the antecedent instruction, cue, or presentation that begins the trial. Examples of SDs in DTT include: 'Touch your nose' (verbal SD for a receptive body part program), showing a picture of a dog and asking 'What is this?' (combined visual + verbal SD for a labeling program), or presenting a number card (visual SD for a math fact program). Stimulus control develops when a behavior occurs reliably in the presence of the SD and not in its absence (i.e., only when the SD is present does the behavior occur). Building strong stimulus control is one of the primary goals of DTT — we want the client to respond to the natural cues in their environment, not to other incidental features of the training context. RBTs deliver SDs clearly and consistently, using the same wording and presentation each time (within the program specifications) to ensure reliable stimulus control. Variability in SD delivery can slow learning and create inconsistent responding.

Question 2: A client is learning to identify colors. When the RBT says 'Point to blue,' the client correctly points to the blue block. The RBT immediately says 'Great job!' and gives a star. What component of the discrete trial does 'Great job!' and the star represent?

The discriminative stimulus (SD)
The inter-trial interval (ITI)
The reinforcing consequence (SR+) (Correct answer)
The error correction procedure

Correct answer: The reinforcing consequence (SR+)

The reinforcing consequence (SR+) is the stimulus delivered following a correct response. In this case, the verbal praise and star are presented contingent on the correct pointing response, functioning as positive reinforcement.

In the three-term contingency (SD → Response → Consequence), the consequence is what follows the response. A reinforcing consequence (SR+) is delivered following a correct response and functions to increase the probability of that response in the future. In this example, the trial structure is: SD = 'Point to blue' → Response = client points to blue block → SR+ = 'Great job!' + star. The praise and star are the positive reinforcers that are presented contingent on the correct response. The quality, immediacy, and consistency of reinforcement delivery are all critical factors in DTT effectiveness. Praise must be enthusiastic and specific ('Great job pointing to blue!'), delivered immediately after the correct response, and paired with the backup reinforcer (the star) consistently. RBTs should also track reinforcer preferences over time to ensure the items and praise being used are maintaining their effectiveness. If correct responding begins to decrease, it may indicate that the reinforcer has lost its effectiveness (satiation) or that it never fully functioned as a reinforcer for this individual.

Question 3: What is 'stimulus control' in the context of discrete trial teaching?

When the client controls which stimuli are used in each trial
When a behavior occurs reliably in the presence of the SD and not in its absence (Correct answer)
When the reinforcement controls the rate of responding
When all distractors in an array are removed so the client only sees the target stimulus

Correct answer: When a behavior occurs reliably in the presence of the SD and not in its absence

Stimulus control exists when a behavior reliably occurs in the presence of a specific stimulus (SD) and does not occur in its absence. Establishing stimulus control is a primary goal of DTT.

Stimulus control refers to the relationship between a stimulus and a behavior — specifically, when a behavior reliably occurs in the presence of a particular stimulus (the SD) and not in its absence. When stimulus control is well established, the behavior is 'under the control of' the SD. In DTT, building stimulus control means that the client learns to respond specifically to the SD and not to other incidental stimuli. For example, a child with good stimulus control for 'touch blue' will reliably select blue when asked, regardless of which position the blue item is in, who gives the instruction, or what room they are in. Poor stimulus control can manifest in several ways: the client responds based on position (always choosing the left item), responds based on the therapist's non-verbal cues, or responds randomly. These patterns indicate that the client has not learned to respond to the intended discriminative stimulus. RBTs can support the development of appropriate stimulus control by using consistent and clear SD presentation, varying the position of target stimuli, rotating distractors, implementing across multiple instructors and settings, and ensuring that only correct responses are reinforced.

Question 4: During a DTT session, a client begins to cry and becomes very upset. The RBT completes the current trial, then pauses the structured session to attend to the client. Which behavior management consideration does this illustrate?

Applying an escape extinction procedure to prevent avoidance of demands
Balancing structured teaching with attentiveness to the client's current emotional/physiological state (Correct answer)
Providing negative reinforcement for crying by allowing a break from demands
Ignoring emotional behavior to prevent reinforcement of escape behavior

Correct answer: Balancing structured teaching with attentiveness to the client's current emotional/physiological state

Effective RBTs balance structured teaching with responsiveness to the client's current state. Pausing a structured session when a client is significantly distressed shows attentiveness to client wellbeing and readiness for learning.

While consistency in program implementation is important, effective RBTs are also attuned to their client's current state. A client who is very distressed, physically unwell, or in crisis is not in an optimal state for learning. Attempting to push through structured teaching during such moments may be counterproductive and potentially harmful. This scenario illustrates the clinical judgment involved in DTT implementation. The RBT completes the current trial to avoid reinforcing escape behavior mid-trial, then appropriately pauses to address the client's distress. This balances consistency with compassion. Determining whether to pause or continue in distress situations depends on several factors: the function of the distress behavior (if it is escape-maintained, pausing may reinforce it), the severity of the distress, the client's overall state, and supervisor guidance. The BIP and skill acquisition programs should include guidance about how to handle these situations. RBTs should communicate with their supervising BCBA about recurring situations where client distress interferes with programming, so clinical decisions about how to handle these situations can be made proactively and included in the program plans.

Question 5: Which of the following BEST describes 'massed practice' in discrete trial teaching?

Presenting trials for many different targets in random rotation during a session
Presenting multiple consecutive trials for the same target with minimal variation (Correct answer)
Spacing training trials for the same target across multiple sessions over several days
Presenting trials in naturalistic settings without a structured format

Correct answer: Presenting multiple consecutive trials for the same target with minimal variation

Massed practice involves presenting multiple consecutive trials of the same target within a short time frame. It is used for initial acquisition to maximize learning opportunities for a single target.

Massed practice (or massed trials) involves repeated consecutive presentation of the same learning objective within a short time window. For example, presenting 10 consecutive trials for the target 'touch nose' is a massed practice approach to teaching that receptive body part. Massed practice maximizes the number of learning opportunities for a specific target in a single session, which can be beneficial during initial acquisition when the client needs many repetitions to learn the new skill. The high density of trials creates frequent opportunities for correct responding and reinforcement delivery. However, massed practice has limitations: it can lead to rote responding (the client may learn to respond to cues other than the SD, like the rhythm of the trials), it may produce satiation of the reinforcer, and it may not promote generalization. For these reasons, it is often used for initial acquisition but then supplemented with distributed practice (spacing trials over time) and varied practice (mixing targets in rotation). RBTs should follow the program specifications regarding massed versus distributed practice. Many programs prescribe a combination — beginning with massed practice and transitioning to maintenance mixed with new acquisition as the skill develops.

Question 6: What is the primary advantage of using a randomized rotation of trials across multiple targets (also called 'random rotation' or 'mixed training') in DTT?

It reduces the number of trials needed to achieve mastery
It prevents rote memorization and promotes true stimulus control by varying the sequence of SD presentations (Correct answer)
It is easier for the RBT to implement than massed trials
It eliminates the need for prompting procedures

Correct answer: It prevents rote memorization and promotes true stimulus control by varying the sequence of SD presentations

Random rotation prevents clients from responding based on trial order or position rather than the SD. It promotes true discriminative responding and reduces error patterns based on pattern memorization.

When trials are presented in a predictable, fixed order, clients may begin to respond based on the sequence (e.g., the answer always follows the pattern A-B-C-A-B-C) rather than responding to the discriminative stimulus itself. This is sometimes called 'stimulus overselectivity' or 'serial position errors' — the client has learned the pattern, not the skill. Random rotation (mixing targets in an unpredictable order) disrupts the ability to use sequence as a cue and requires the client to actually discriminate between SDs on each trial. This tests and strengthens true stimulus control — the client must attend to the SD itself to know how to respond. For example, in a colors program, randomly alternating between 'touch red,' 'touch blue,' and 'touch green' requires the client to respond to the spoken color label each time, rather than memorizing a predictable pattern. This is a more valid test of what has been learned. RBTs should implement the trial rotation format specified in each program. Many programs use randomized rotations with data recorded by target, so that progress on each individual target is trackable. Understanding why rotation is clinically important helps RBTs implement it with fidelity rather than defaulting to predictable sequences.

RBT Discrete Trial Training 2

In a discrete trial, what is the function of the discriminative stimulus (SD)?