DRO stands for differential reinforcement of other behavior, and it’s one of the most widely used techniques in applied behavior analysis (ABA) for reducing problem behaviors. The core idea is simple: instead of punishing an unwanted behavior, you reinforce its absence. If a specific problem behavior doesn’t occur for a set period of time, the person earns a reward. Over time, this increases the gap between occurrences of the behavior until it fades significantly or stops altogether.
How DRO Actually Works
A DRO procedure starts a timer. If the target behavior doesn’t happen before the timer runs out, the person receives reinforcement, which could be verbal praise, a preferred toy, a snack, or whatever is meaningful to that individual. If the behavior does occur, the timer resets and starts over. The person only earns the reinforcer by going the full interval without engaging in the problem behavior.
Here’s a concrete example: a child throws tantrums to get access to a preferred toy. A therapist sets a five-minute DRO interval. If the child goes the full five minutes without a tantrum, they get praise and brief access to the toy. If a tantrum happens at minute three, the timer resets to zero. The child needs another full five minutes of tantrum-free time to earn the reinforcer.
What makes DRO distinctive is that it doesn’t require a specific replacement behavior. The child could be sitting, drawing, humming, or doing anything else during that interval. The only condition is the absence of the targeted problem behavior.
Setting the Initial Interval
The starting interval isn’t arbitrary. Practitioners typically collect baseline data on how often the problem behavior occurs, then set the initial DRO interval at roughly half the average time between occurrences. In one study, researchers calculated baseline responding and set starting intervals at 9 seconds, 13 seconds, and 4 seconds for three different participants. Those numbers sound short, but the point is to start where the person can actually succeed, then build from there.
If the interval is too long from the start, the person never earns reinforcement, which can cause frustration and make the whole procedure backfire. A practical, achievable interval is essential. The goal is early wins that build momentum.
Types of DRO Schedules
Not all DRO schedules work the same way. The two major distinctions are between interval and momentary schedules, and between fixed and variable timing.
- Fixed-interval DRO: The timer is always the same length (say, two minutes every time), and the person must go the entire interval without the behavior. This is the most common and best-studied version.
- Variable-interval DRO: The timer length changes unpredictably around an average (sometimes 90 seconds, sometimes 150 seconds, averaging two minutes). This makes it harder for the person to predict exactly when reinforcement is coming, which can help maintain behavior change.
- Momentary DRO: Instead of monitoring behavior throughout the whole interval, the practitioner only checks whether the behavior is happening at the exact moment the timer goes off. This is easier to implement but less reliable.
Research comparing these approaches has found that fixed-interval, variable-interval, and variable-momentary DRO schedules are equally effective at reducing problem behavior. Fixed-momentary DRO, however, has generally been ineffective. The likely reason is that a predictable schedule combined with only a single-second check gives the person too much unmonitored time, making it easy to engage in the behavior without consequence.
Increasing the Interval Over Time
Once the person consistently succeeds at the starting interval, practitioners gradually increase it. This process is called schedule thinning. The typical rule of thumb is to increase the interval after a few consecutive sessions of sustained behavior reduction, often after two or three successful trials in a row. If the behavior spikes again after an increase, the practitioner drops back to the previous interval and holds there longer before trying again.
The long-term goal is to stretch the interval out far enough that reinforcement is only delivered occasionally, which mirrors how the real world works. A child who once needed reinforcement every 10 seconds for not hitting might eventually go an entire class period without the behavior, earning a reward at the end.
Limitations to Be Aware Of
DRO has a well-known blind spot: because it reinforces the absence of one specific behavior, it technically reinforces whatever else the person happens to be doing when the timer ends. If a child stops hitting but starts kicking instead, and the timer runs out during a kick, the kicking gets reinforced. Practitioners need to monitor for this kind of unintended reinforcement of other inappropriate behaviors.
Frustration is another real concern. When a person engages in the problem behavior just before the interval ends, the timer resets and they lose access to the reinforcer they were close to earning. For some individuals, especially those with limited communication skills, repeated resets can escalate frustration and temporarily worsen behavior. This is why setting a realistic starting interval matters so much.
How DRO Differs From DRA and DRI
DRO is one of several differential reinforcement strategies, and understanding the differences helps clarify when each is most useful.
- DRA (differential reinforcement of alternative behavior) reinforces a specific replacement behavior that serves the same function as the problem behavior. If a child screams for attention, DRA would reinforce them for raising their hand instead. The replacement must be functionally equivalent to the problem behavior.
- DRI (differential reinforcement of incompatible behavior) reinforces a behavior that physically cannot happen at the same time as the problem behavior. If a child throws objects, DRI might reinforce keeping hands in their lap, since you can’t throw something while your hands are folded.
- DRO reinforces any behavior other than the problem behavior. It doesn’t require identifying a specific alternative or incompatible behavior, which makes it useful when no clear replacement has been identified.
DRA and DRI are generally preferred when a suitable replacement behavior exists, because they actively build a new skill. DRO is often the strategy of choice when the priority is simply reducing a dangerous or disruptive behavior quickly, or when it’s difficult to pinpoint a single alternative behavior to reinforce. In practice, clinicians frequently combine DRO with other strategies, using it to suppress the problem behavior while simultaneously teaching a functional replacement through DRA or DRI.