ABA Exam Coach

G.6: Design and evaluate procedures to produce simple and conditional discriminations.

Free practice questions for this part of the BCBA, with an explanation for every option.

A learner labels every four-legged animal "dog." The therapist gives praise only when "dog" is said in the presence of dogs, and gives no reinforcement when it is said for cats, horses, or cows. This procedure is best described as:
  1. A. Conditional discrimination training
    In a conditional discrimination, the correct response depends on a second (sample) stimulus. No sample is described here.
  2. B. Response generalization training
    Response generalization involves untrained responses. Here, one trained response is brought under specific stimulus control.
  3. C. Discrimination training (differential reinforcement in the presence of SD and S-delta)
    Correct. Reinforcing a response in the presence of one stimulus and withholding reinforcement in the presence of others builds a simple discrimination.
  4. D. Stimulus generalization training
    The learner is already overgeneralizing. The procedure narrows stimulus control instead of broadening it.
During a matching-to-sample task, the therapist says "touch red" or "touch blue" with two color cards on the table. Data show 100% accuracy, but the correct card was in the left position on every trial. What is the best revision?
  1. A. Add a third color card while keeping the correct card on the left
    Keeping the left position correct still allows position control.
  2. B. Move on to the next target, since the learner meets mastery criteria
    These accuracy data do not show the intended conditional stimulus control, so mastery is not established.
  3. C. Randomize and counterbalance the positions of the comparison stimuli across trials
    Correct. When position is confounded with correctness, responding may be under control of position. Counterbalancing makes sure the auditory sample controls the selection.
  4. D. Increase reinforcement for correct responses to strengthen the discrimination
    Stronger reinforcement would likely strengthen the position bias.
On every trial, a picture of a car and a picture of a shoe are on the table, and their positions are randomized. When the therapist says "car," the child touches the car. When the therapist says "shoe," the child touches the shoe. This performance is best described as:
  1. A. A conditional discrimination, because which picture is correct depends on the spoken word
    Correct. Each picture is correct on some trials and incorrect on others, depending on the spoken sample. When the function of a stimulus depends on another stimulus, the relation is a conditional discrimination.
  2. B. A simple discrimination, because each picture always occasions the same touching response
    In a simple discrimination, one stimulus is always the S+. Here, neither picture is always correct.
  3. C. Stimulus generalization, because the child responds similarly to both of the pictures
    Generalization means similar responding to stimuli that share features. The child is responding differently to the two pictures, which shows discrimination.
  4. D. An echoic relation, because the child's response is controlled by a vocal stimulus
    An echoic is a vocal response that matches a vocal stimulus in form. Touching a picture is a selection response, not an echoic.

Take the free diagnostic