B.17: Distinguish between motivating operations and stimulus control.
Free practice questions for this part of the BCBA, with an explanation for every option.
Ella asks for juice much more often on hot days after recess. She asks only when her aide, who keeps the juice, is nearby. Which analysis correctly identifies the variables?
- A. The heat and the aide's presence are both motivating operationsIncorrect. The aide's presence does not change the value of juice. It signals that asking will be reinforced.
- B. The heat is a discriminative stimulus and the aide's presence is an establishing operationIncorrect. This reverses the functions of the two variables.
- C. The heat and the aide's presence are both discriminative stimuliIncorrect. Heat does not signal that juice is available. It raises how much juice is worth.
- D. The heat is an establishing operation and the aide's presence is a discriminative stimulusCorrect. Heat and exertion raise the reinforcing value of juice (EO). The aide's presence is correlated with juice being available (SD).
Which statement best distinguishes a motivating operation from a discriminative stimulus?
- A. An MO changes the current effectiveness of a consequence, while an SD evokes behavior because reinforcement has been more available in its presenceCorrect. The core difference is value-altering (MO) versus availability-signaling based on a history of differential reinforcement (SD).
- B. An SD changes the value of a reinforcer, while an MO signals whether the reinforcer is availableIncorrect. This reverses the two functions.
- C. Both require a history of differential reinforcement to affect behaviorIncorrect. Unconditioned MOs, such as food deprivation, do not depend on a learning history.
- D. MOs only decrease behavior, while SDs only increase behaviorIncorrect. MOs have both evocative and abative effects, and an SD can occasion responses that are later punished or reduced.
During an interrupted-chain procedure, an RBT gives 6-year-old Rosa a clear jar of her favorite crackers with the lid screwed on too tightly for her to open. Rosa then says "Open" to the RBT. In this analysis, the tightly closed jar is best classified as a(n):
- A. Discriminative stimulus, because it signals that help is availableAn SD signals that reinforcement is available for a response. The jar does not signal that help is available, since the RBT is equally available with or without it. What the jar changes is how valuable help is.
- B. S-delta, because opening the jar alone is not reinforcedAn S-delta is a stimulus in whose presence a response has not been reinforced. The jar evokes manding rather than suppressing it.
- C. Unconditioned motivating operation that increases the value of crackersUMOs, such as food deprivation, change reinforcer value without a learning history. The jar's effect depends on a learned chain and makes help valuable, not the crackers.
- D. Transitive conditioned motivating operation that makes help valuableCorrect. A blocked step in a chain makes another stimulus (help or opening) valuable as a reinforcer and evokes behavior that has produced it. That is a CMO-T, a motivating operation rather than a form of stimulus control.