The same snack can be a powerful reinforcer at 11:45 and nearly worthless at 12:30. Nothing about the snack changed. What changed is the learner's motivation, and behavior analysts describe that change with motivating operations.
Why it matters
A reinforcer is not a fixed property of an item. Its effectiveness rises and falls with deprivation, satiation, discomfort, and context. Ignore those conditions and a program that worked yesterday can look like it failed today.
Motivating operations also explain why problem behavior clusters at certain times (before lunch, after a poor night's sleep, during long writing tasks) and give you tools to change behavior before it happens. Mand training depends on them, because a mand is controlled by what the learner wants right now. Task B.16 is about recognizing MOs in examples: naming the type of MO and the effect it produces.
Key ideas
- Every MO has two effects. It changes how effective some stimulus is as a reinforcer or punisher (the value-altering effect), and it changes how often behavior that has produced that stimulus occurs right now (the behavior-altering effect).
- Direction matters. An establishing operation (EO) increases a stimulus's effectiveness as a reinforcer. An abolishing operation (AO) decreases it. The matching behavior-altering effects are evocative (more of the related behavior) and abative (less of it).
- The effects are momentary. An MO changes current frequency, not the learner's repertoire. When the MO ends, behavior returns to its usual level. Learning, by contrast, leaves a lasting change.
- The behavior-altering effect does not need reinforcement right now. A thirsty learner asks for water more often before any water arrives, and even for a while during extinction. The MO plus the learner's history with water evokes the asking.
- Unconditioned vs. conditioned. A UMO gets its value-altering effect without any learning history: food, water, or sleep deprivation and satiation, temperature extremes, and painful stimulation. A CMO gets its value-altering effect through learning.
- Three kinds of CMO.
- Surrogate (CMO-S): a stimulus that was paired with another MO comes to have that MO's effects.
- Reflexive (CMO-R): a stimulus that has reliably come before worsening conditions makes its own removal effective as a reinforcer. Warning signals before hard demands are the classic case.
- Transitive (CMO-T): an environmental change makes another stimulus effective as a reinforcer and evokes behavior that has produced it. Needing a tool you do not have is the textbook example.
- MOs also apply to punishers. Taking away a privilege only works as punishment when access to that privilege currently matters to the learner.
Definitions
- Motivating operation (MO): an environmental variable that momentarily changes the effectiveness of a stimulus as a consequence and the current frequency of behavior that has produced that consequence.
- Value-altering effect: an increase (establishing) or decrease (abolishing) in a stimulus's effectiveness as a reinforcer or punisher.
- Behavior-altering effect: an increase (evocative) or decrease (abative) in the current frequency of behavior that has been followed by that stimulus.
- Deprivation and satiation: going without a reinforcer usually establishes its value; recent, plentiful access usually abolishes it.
Examples from a session
Four MOs you might see this week
- UMO, satiation (AO): Amara, 5, arrives at the clinic after a large breakfast. Her usual crackers barely change her responding. Her RBT switches to a toy she has not played with in a few days.
- CMO-T: During a snack routine at home, Wen, 8, gets a yogurt but no spoon. The missing spoon makes a spoon valuable and evokes "Spoon, please," a mand his team is teaching through planned interruptions like this one.
- CMO-R: Mr. Okafor, 62, attends an adult day program. He starts pacing and leaving the table as soon as staff set out the clipboard that has always come before long intake forms. The clipboard warns of worse conditions, so its removal works as a reinforcer.
- CMO-S: A therapy room has often been very cold. Now Rosa, 11, asks for her sweater as soon as she enters, even on warm days, because the room has come to function like the cold it was paired with.
- Non-example (SD, not MO): Jordan, 6, signs "bubbles" only when Kim is holding the bubble jar. His wanting has not changed; the jar in Kim's hand signals that bubbles are available.
Interventions often use MOs (brief, planned limits on a preferred toy before mand practice) or change them (breaks, choices, or easier tasks that lower the value of escape). Any restriction should be brief, ethically reviewed, and never involve food, water, or sleep.
Common mistakes / exam traps
- Calling an MO an SD. An SD signals that reinforcement is available. An MO changes how much the reinforcer is worth. This comparison gets its own lesson in B.17.
- Mixing up the vocabulary. Establishing and abolishing describe the value-altering effect. Evocative and abative describe the behavior-altering effect.
- Treating MOs as permanent. A learner who refuses a snack after lunch has not lost interest in it forever.
- Classifying the MO by the reinforcer. Money is a conditioned reinforcer, but that tells you nothing about the MO. Ask whether the variable that changed its value right now needed a learning history to have that effect.
Exam trap
UMO vs. CMO: decide by whether learning was needed for the value change, not by the reinforcer. First ask whether a consequence's value is going up (EO) or down (AO) and whether the related behavior is happening more or less right now.
Exam trap
CMO-T vs. CMO-R: ask what becomes valuable. If the condition makes something else valuable (a tool, a missing spoon), it is a CMO-T. If it makes its own removal valuable because it warns of something worse (a folder before long writing), it is a CMO-R.
Quick check
Kai, 10, has had no screen time since breakfast. The tablet is never given during work periods, yet this afternoon he asks for it far more often than he does on mornings right after screen time. Which effect best explains the rise in asking?
Related topics
- Kinds of reinforcers: unconditioned, conditioned, and generalized (B.7)
- Recognizing stimulus control (B.12)
- Motivating operations vs. stimulus control (B.17)
- The verbal operants: mand, tact, echoic, intraverbal, and more (B.19)
- Designing and evaluating preference assessments (F.4)
- Building motivating operations and discriminative stimuli into interventions (G.5)