Differential reinforcement of incompatible behavior

Incompatibility must be observable and simultaneous

A DRI plan defines two response classes. One is the target response. The other is the response that earns reinforcement and is physically impossible to perform at the same time.

Examples depend on precise definitions:

• both hands carrying a tray is incompatible with either hand sweeping its contents
• sitting in a chosen chair is incompatible with standing at that instant
• speaking at a conversational volume is incompatible with shouting during the same vocal response

Broad labels such as “calm,” “safe,” or “appropriate” do not establish incompatibility. Responses that merely compete for time or attention may still occur together. When simultaneous occurrence remains possible, the procedure is DRA rather than DRI.

The ABAI basic-principles page lists differential reinforcement in higher-education content. The BACB BCBA Test Content Outline, 6th edition covers designing and evaluating differential-reinforcement procedures with and without extinction. These sources describe training and examination content, not a case-specific protocol.

Physical fit does not establish functional fit

An incompatible response can fail when it produces the wrong outcome. If sweeping materials reliably ends a difficult task, reinforcing hands in a lap with praise may offer neither escape nor useful help. The selected response should obtain the relevant outcome, or the environment should change so the original barrier is resolved.

Ask whether the response is:

• chosen or meaningfully agreed to by the person
• available in the relevant setting and moment
• physically comfortable and within the person's repertoire
• faster or at least as efficient as the target response
• recognizable to ordinary communication partners
• connected to a reinforcer that is valuable then

A broad evidence review describes DRI as reinforcing behavior that is physically impossible alongside the target response. The review groups DRI with other differential-reinforcement practices rather than treating incompatibility as a complete treatment rationale (Hume and colleagues).

How DRI relates to DRA

Every DRI response is an alternative response, but many alternatives are compatible with the target. A person can ask for a break while continuing another response, so functional communication training often uses DRA without meeting the stricter DRI definition.

The Tiger, Hanley, and Bruzek review explains response effort, recognizability, and partner responsiveness in functional communication training. These same design questions help a DRI response compete outside teaching sessions.

DRI also differs from differential reinforcement of other behavior. DRO requires the target response to be absent for a defined period or at a defined moment. It does not specify which other response must occur.

Prompts, reinforcement, and fading need separate data

Define independent responding and each prompt level before teaching begins. Provide enough time for the person to respond, use the least assistance that works, and fade prompts from observed performance. Report prompted and independent responses separately.

A review by Vladescu and Kodak discusses differential reinforcement during skill acquisition and the need to reduce prompt dependence. It does not establish one prompt sequence for every learner.

Partner behavior belongs in the plan. Measure whether the partner notices the response and provides the promised consequence within the defined time. A response cannot compete reliably when partners miss it or delay the outcome.

A fictional DRI example

Leila is a fictional eleven-year-old who wants an easier way to end a tabletop activity and take a break. An eligible opportunity begins when Leila selects “finished” and loose materials remain on a tray. Sweeping materials from the tray and carrying it with both hands to a marked return shelf are scored separately before any prompt. Carrying the tray is physically incompatible with sweeping it by hand at that moment.

Across six baseline opportunities, Leila sweeps materials in 5 of 6 and independently carries the tray in 0 of 6. Adults end the activity within ten seconds after 5 of 5 sweeping responses. These descriptive counts suggest that ending the activity may matter, while leaving function unproven.

Leila chooses the tray option. The team reduces the load, places the shelf nearby, teaches the movement, and provides an immediate chosen break after the tray reaches the shelf. Across eight later opportunities, Leila independently carries the tray in 6 of 8, adults start the break within ten seconds in 6 of 6, and sweeping occurs in 2 of 8.

Teaching, tray weight, shelf distance, and adult response all changed together. The result describes performance under the package and cannot isolate DRI as the cause. Leila rates 7 of 8 endings comfortable. The team retains the lighter tray and nearby shelf because environmental supports are part of a workable routine.

Protect communication, assent, and essential access

ASHA's AAC practice portal says AAC users should always have access to their tools or devices. A motor response should never replace access to speech, AAC, gesture, writing, or another effective communication form. Honor recognizable requests, dissent, discomfort, and safety messages even when the exact DRI response is absent.

Food, water, bathroom use, mobility, prescribed care, pain care, rest, relationships, and emergency help remain available regardless of performance. Pause on distress or withdrawal when assent applies, unless an immediate safety or legal duty governs. Avoid selecting an incompatible response merely because it makes a person look quieter or more typical.

The current BACB Ethics Code applies to BCBA and BCaBA certificants and people who completed an application. It addresses client involvement, consent and assent when applicable, assessment, medical needs, risk, positive reinforcement, data, and ongoing evaluation.