An establishing operation (EO) is any condition or event that temporarily increases the value of a particular reinforcer and, at the same time, increases the frequency of behaviors that have previously led to that reinforcer. It’s one of the most important concepts in applied behavior analysis because it explains why the same person might respond very differently to the same situation at different times. A child who just finished lunch won’t work for a snack, but a child who hasn’t eaten in hours will do almost anything for one. The difference isn’t the snack or the task. It’s the establishing operation.
How an EO Changes Both Value and Behavior
An establishing operation produces two distinct effects that always work together. The first is called the value-altering effect: it changes how reinforcing something is at that moment. Food deprivation, for example, makes food more valuable as a reinforcer. The second is the behavior-altering effect, sometimes called the evocative effect: it increases the frequency of any behavior that has previously resulted in accessing that reinforcer. When you’re hungry, you don’t just want food more. You also open the fridge more often, drive to restaurants, ask someone what’s for dinner. All of those behaviors increase because the EO is in place.
These two effects are inseparable. You can’t have an increase in reinforcer value without a corresponding increase in the behaviors linked to that reinforcer. This is what makes the EO such a powerful variable in behavior analysis. It doesn’t just make someone “want” something in an abstract sense. It actively changes the rate at which specific, observable behaviors occur.
EOs vs. Abolishing Operations
The establishing operation is one half of a broader category called motivating operations (MOs). The other half is the abolishing operation (AO), which does the exact opposite: it decreases the value of a reinforcer and reduces the behaviors associated with it. Satiation is the most intuitive example. After eating a large meal, food loses its reinforcing power, and you stop engaging in food-seeking behavior.
Research on attention-maintained problem behavior illustrates this contrast clearly. In one study, children who were deprived of attention (the EO condition) showed problem behavior rates of 13 to 20 percent during test sessions. Children who received generous attention beforehand (the AO condition) showed rates of 0 to 6 percent. Same children, same environment, same consequences available. The only variable that changed was whether an EO or AO was in effect.
Unconditioned vs. Conditioned EOs
Some establishing operations are built into human biology and don’t require any learning history. These are called unconditioned EOs (sometimes abbreviated UEOs or UMOs). Food deprivation, water deprivation, sleep deprivation, painful stimulation, and uncomfortable temperatures all fall into this category. If you haven’t slept in 36 hours, rest becomes an extremely powerful reinforcer, and you’ll engage in all sorts of behaviors to access it. No one had to teach you that.
Conditioned establishing operations, by contrast, acquire their effects through a person’s individual learning history. A locked door, for example, has no inherent motivating properties. But once a person has learned that a key opens a locked door, encountering a locked door establishes the key as a reinforcer and evokes key-seeking behavior. The locked door functions as a conditioned EO because its value-altering and behavior-altering effects depend entirely on past experience.
Behavior analysts have historically focused more on unconditioned EOs like hunger and thirst, but conditioned EOs are arguably more relevant to everyday clinical work. Many of the establishing operations that drive problem behavior in applied settings, such as deprivation of attention, removal of preferred items, or the presence of difficult task demands, involve learned relationships rather than biological drives.
How EOs Differ From Discriminative Stimuli
One of the most common points of confusion in ABA is the difference between an establishing operation and a discriminative stimulus (SD). Both influence behavior, but they do so in fundamentally different ways. A discriminative stimulus signals that a particular reinforcer is available if the person engages in a specific behavior. It answers the question “Can I get it right now?” An establishing operation changes whether the person cares about that reinforcer in the first place. It answers the question “Do I want it right now?”
Consider a vending machine. The sight of the machine is a discriminative stimulus: it signals that inserting money will produce a snack. But whether you actually walk over and use it depends on whether an EO is in effect. If you just ate, the machine is irrelevant. If you’re hungry, the machine suddenly matters. Jack Michael, the behavior analyst who formalized the EO concept in 1982, made this distinction explicit in his definition of the discriminative stimulus, noting that an SD only increases behavior “given the momentary effectiveness of some particular type of reinforcement.” That momentary effectiveness is determined by the EO.
The two variables also interact. An EO strongly influences whether a given discriminative stimulus will actually trigger behavior, and the discriminative stimulus influences which specific behavior occurs once the EO has made a reinforcer valuable. A hungry person (EO in effect) will respond differently to a restaurant sign (one SD) than to a grocery store sign (another SD), but neither sign matters much without the hunger.
Practical Applications in ABA Therapy
Understanding establishing operations gives practitioners a way to influence behavior without changing consequences at all. Instead of modifying what happens after a behavior, you modify the conditions that exist before it. This is particularly useful in two directions: increasing desirable behavior and decreasing problem behavior.
To increase motivation for learning or communication, therapists often create mild deprivation of preferred items. A therapist might limit access to a favorite toy before a session, which establishes that toy as a more powerful reinforcer. The child is then more motivated to perform a target behavior, such as using words or signs to request the toy, because the EO has made the toy temporarily more valuable. This technique is common in teaching communication skills to children with autism.
To decrease problem behavior, therapists do the reverse. If a functional assessment reveals that a child’s disruptive behavior is maintained by attention, providing generous, high-quality attention before and during activities serves as an abolishing operation. The attention is no longer scarce, so its reinforcing value drops, and the behaviors that previously produced it decrease. Research consistently shows that presession access to the relevant reinforcer (whether attention, tangible items, or sensory input) reduces problem behavior during subsequent sessions.
Identifying EOs in Assessment
Functional behavior assessments rely heavily on identifying which establishing operations are in effect when problem behavior occurs. An analyst observes the conditions surrounding the behavior: Has the person been deprived of attention? Are aversive demands present? Is there limited access to preferred activities? These conditions point to specific EOs that make particular reinforcers (escape, attention, tangible items) momentarily more valuable.
Once the relevant EO is identified, treatment can target it directly. If attention deprivation is the EO driving problem behavior, the intervention focuses on ensuring regular, noncontingent attention throughout the day. If the presence of difficult tasks creates an EO for escape, the intervention might involve modifying task difficulty or interspersing easier tasks. This approach treats the root motivational condition rather than just managing consequences after the behavior has already occurred, which tends to produce more durable and meaningful behavior change.