What Are Motivating Operations?
Motivating operations (MOs) are environmental variables that have two defining effects: they alter the reinforcing or punishing effectiveness of a consequence (value-altering effect), and they alter the current frequency of behavior related to that consequence (behavior-altering effect). MOs are distinct from discriminative stimuli, which signal that reinforcement is available but do not change the value of the reinforcer itself.
Establishing Operations
An establishing operation (EO) increases the reinforcing effectiveness of a stimulus and increases the frequency of behavior that has produced that stimulus in the past. Example: food deprivation (not eating for several hours) is an EO for food. It makes food more reinforcing (value-altering effect) and increases behaviors that have previously resulted in obtaining food, such as going to the kitchen or asking for a snack (behavior-altering effect).
Abolishing Operations
An abolishing operation (AO) decreases the reinforcing effectiveness of a stimulus and decreases the frequency of behavior that has produced that stimulus. Example: eating a large meal is an AO for food. It makes food less reinforcing and decreases food-seeking behaviors.
MO vs. SD
This distinction is frequently tested on the BCBA exam. A discriminative stimulus (SD) signals that reinforcement is available for a particular response, but it does not change the value of the reinforcer. An MO changes the value of the reinforcer itself. Example: a vending machine (SD) signals that inserting money will produce a snack. Being hungry (EO) makes the snack more valuable. The vending machine does not make you hungry; hunger makes the snack worth buying.
Types of MOs
Unconditioned MOs (UMOs) are unlearned and related to biological needs: food deprivation, water deprivation, sleep deprivation, temperature changes, and painful stimulation. Conditioned MOs (CMOs) are learned through experience. CMO-S (surrogate) acquires its MO effects through pairing. CMO-R (reflexive) makes its own removal reinforcing (e.g., the warning tone before a shock). CMO-T (transitive) establishes the reinforcing value of a stimulus needed to access another reinforcer (e.g., a locked door makes a key more reinforcing).