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G.2: Design and evaluate differential reinforcement (e.g., DRA, DRO, DRL, DRH) procedures with and without extinction.

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

A clinician sets a timer for 2-minute intervals. At the end of each interval, the client gets a preferred item only if no self-injury occurred at any point during that interval. If self-injury occurs, the timer resets. Which procedure is this?
  1. A. Fixed-time reinforcement
    Fixed-time schedules deliver reinforcers no matter what behavior occurs.
  2. B. Momentary DRO
    Momentary DRO checks only whether the behavior is absent at the moment the interval ends.
  3. C. Whole-interval (resetting) DRO
    Correct. Reinforcement requires the target behavior to be absent for the entire interval, and responding resets the interval.
  4. D. DRL with a 2-minute interresponse time
    DRL reinforces the target behavior when it occurs at a low rate. It does not require the behavior to be absent.
A high school student asks relevant questions in class, but asks about 15 per period, which disrupts instruction. The teacher wants the student to keep asking questions at a lower rate. Which procedure is most appropriate?
  1. A. Differential reinforcement of high rates (DRH)
    DRH would increase the rate of question asking, which is the opposite of the goal.
  2. B. Differential reinforcement of low rates (DRL)
    Correct. DRL reduces a behavior's rate while keeping it in the repertoire, which suits behavior that is only a problem when it is too frequent.
  3. C. Whole-interval DRO
    DRO reinforces the absence of the behavior and would tend to eliminate a behavior that is useful at a lower rate.
  4. D. Differential reinforcement of incompatible behavior
    DRI replaces the behavior with a physically incompatible one, which removes question asking altogether.
A child's attention-maintained screaming is treated with DRA: the child gets attention for using a picture card. The family says they cannot ignore screaming, so screaming still gets attention about half the time. Screaming has decreased only slightly. Which change is most likely to improve the outcome without needing extinction?
  1. A. Adding a 10-second delay before attention is delivered for card use
    Delaying reinforcement for the alternative makes it relatively weaker and shifts the balance toward screaming.
  2. B. Thinning reinforcement for card use to FR 3 to build persistence
    Thinning too early makes the alternative less efficient than screaming.
  3. C. Switching to a momentary DRO schedule for screaming
    Changing to DRO does not solve the main problem, which is that screaming is still reinforced.
  4. D. Making reinforcement for card use richer than reinforcement for screaming (more immediate, longer, and higher quality attention)
    Correct. When extinction cannot be used, DRA can still work if the parameters of reinforcement (rate, quality, immediacy, magnitude) favor the alternative response.

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