By Matt Harrington, BCBA · Behaviorist Book Club · Research-backed answers for behavior analysts
Code 2.01 requires behavior analysts to rely on current scientific knowledge in their professional work. The evidence-based practice model integrates three elements: the best available research evidence, clinical expertise, and client values and preferences. All three are required — research alone is insufficient if it is applied without clinical judgment or without consideration of the specific client's priorities. Code 2.09 operationalizes the client values component, and Code 2.14 operationalizes the ongoing evaluation requirement. Together, these provisions describe an evidence-based practice obligation that is explicitly individualized and continuous.
Go directly to the peer-reviewed literature rather than relying on marketing materials or program descriptions. Examine the populations studied, the research designs used, the outcomes measured, and the quality of the evidence. Single-case experimental designs with replication are the primary research method in ABA; evaluate whether the replications are sufficiently diverse to support generalization to your client's population. Check whether outcomes were measured on dimensions relevant to your client — not just skill acquisition but generalization, maintenance, and quality-of-life indicators. Be appropriately skeptical of claims that are not supported by peer-reviewed evidence, even when they are advanced by recognized practitioners.
Barriers fall into several categories that require different responses. Motivational barriers include insufficient reinforcer value, satiation, or a history of thin reinforcement schedules that have not maintained responding. Instructional barriers include inappropriate prompt levels, unclear stimulus control, poorly defined instructional targets, or mismatch between task complexity and current repertoire. Environmental barriers include inconsistent implementation across settings or people, distracting stimuli, or insufficient practice opportunities. Biological barriers include sleep disruption, medical conditions, sensory sensitivities, or medication changes. Systematic assessment of each category before changing core procedures prevents the mistake of abandoning effective approaches because a secondary barrier has not been identified and addressed.
Modification starts with individual assessment: what does this specific client's data show, and what does analysis of their learning history suggest about why? From there, modifications typically fall into a few categories: adjusting reinforcer selection and delivery based on the client's current motivational state; adjusting prompt level and prompt fading procedures based on the client's error rate and learning curve; adjusting task difficulty and sequencing based on the client's current repertoire; and adjusting session structure based on the client's attention, fatigue, and engagement patterns. Each modification should be driven by specific data and clinical reasoning, and its effect should be monitored systematically.
Code 2.14 requires behavior analysts to continuously evaluate the effectiveness of treatment and to modify, discontinue, or recommend alternative treatment when the current approach is not producing adequate progress. This is an active obligation, not a passive one — practitioners cannot simply document non-progress and continue without responding. The practical implication is that progress review meetings should result in actual program decisions: continue as-is when progress is adequate, modify when progress is insufficient, and consider referral or alternative approaches when modification has not resolved the problem.
Code 2.09 requires behavior analysts to consider client and family preferences, but Code 2.01 requires those preferences to be balanced against scientific evidence. The appropriate response is transparent communication: explain what the evidence shows about the requested approach, what its limitations are, and what alternatives have stronger evidence for this client's specific goals. If the family continues to request the approach after being fully informed, the practitioner must exercise professional judgment about whether implementing it is consistent with Code 2.01. Implementing an approach with no evidence or with evidence of harm is not supported by the Ethics Code regardless of family preference.
Professional disagreement about the best available evidence for a specific client is expected and healthy. Code 2.01 requires reliance on scientific knowledge, not consensus — and scientific knowledge in ABA is a moving and sometimes contested body of evidence. When practitioners disagree, the appropriate process is to examine the evidence directly, consider how each approach maps onto the specific client's characteristics, and attempt to reach agreement through data-based deliberation. When agreement cannot be reached, supervision, peer consultation, and, in cases of significant disagreement, ethics consultation are appropriate next steps.
Code 2.01 does not require practitioners to implement any specific procedure — it requires them to base practice on scientific knowledge and to individualize based on the client's needs and response to treatment. Modifying a popular procedure because the client's data indicate that modification is needed is not only ethically permissible — it is ethically required. The alternative — rigidly maintaining a procedure that is not producing adequate progress for a specific client because the procedure has general empirical support — fails the individualization requirement that the evidence-based practice model and the Ethics Code both demand.
Treatment plans should document the evidence base for each selected intervention, the client-specific factors that informed procedure selection, and the data criteria that will be used to evaluate progress and trigger modification. For each goal, the plan should articulate why this target was selected for this client at this time, what procedure will be used and why it is appropriate given the client's current repertoire, and what progress data will be collected and reviewed. This documentation serves the practitioner, the family, and any oversight reviewers — and it makes the individualization that evidence-based practice requires explicit and reviewable.
Clinical expertise bridges the gap between population-level research evidence and individual client decisions. Research establishes what works for groups of individuals with certain characteristics; clinical expertise determines how to apply that knowledge to a specific individual whose characteristics partially overlap with but are not identical to research populations. Experienced clinicians recognize patterns, anticipate implementation challenges, and adapt procedures more efficiently than those who are applying research evidence for the first time. This expertise is not a substitute for research knowledge — it is what allows research knowledge to be applied skillfully. Both are required by the evidence-based practice model.
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All behavior-analytic intervention is individualized. The information on this page is for educational purposes and does not constitute clinical advice. Treatment decisions should be informed by the best available published research, individualized assessment, and obtained with the informed consent of the client or their legal guardian. Behavior analysts are responsible for practicing within the boundaries of their competence and adhering to the BACB Ethics Code for Behavior Analysts.