By Matt Harrington, BCBA · Behaviorist Book Club · April 2026 · 12 min read

Telehealth vs. In-Person Discrete Trial Teaching: What the Evidence Says

Overview & Clinical Significance

The expansion of telehealth-based behavior analytic services during and after the COVID-19 pandemic forced the field to confront a fundamental question: does service delivery modality affect skill acquisition outcomes? Discrete trial teaching (DTT) is one of the most extensively researched instructional technologies in ABA, with a robust evidence base supporting its use across populations and skill domains. However, the vast majority of that evidence base was generated in face-to-face contexts, leaving practitioners without a clear empirical foundation when pivoting to virtual delivery.

This study by Dr. Justin Leaf directly addresses that gap by systematically comparing DTT outcomes across telehealth and in-person conditions. For clinicians, this comparison matters on multiple levels. At the individual client level, it informs decisions about whether telehealth is a functionally equivalent alternative or a meaningful compromise. At the systems level, it shapes staffing models, insurance justification, and program design. At the ethical level, Code 2.01 of the BACB Ethics Code requires that practitioners use evidence-based practice and provide services that are effective — which means service delivery modality is not merely a logistical choice but an ethical one.

Understanding this research is particularly relevant for supervisors, clinical directors, and BCBAs who make access-related decisions on behalf of clients who may live in rural or underserved areas where in-person services are limited or unavailable. Telehealth may expand reach — but only if the clinical fidelity is sufficient to produce equivalent outcomes. This course provides the data practitioners need to make that determination rather than relying on assumption.

Background & Context

DTT as a formalized instructional procedure traces its lineage to early applied work emerging from the experimental analysis of behavior. Its core components — discriminative stimulus, response opportunity, consequence, and inter-trial interval — were standardized to create a high-density teaching format that maximizes learning trials per session. This structure has proven effective for teaching a wide range of skills including receptive and expressive language, academic readiness, imitation, and daily living skills.

Prior to COVID-19, telehealth in ABA was used primarily for parent training, supervision, and consultation rather than direct one-to-one instructional delivery. The pandemic compressed what might have been a decade of gradual adoption into months, with many providers transitioning entire caseloads to remote platforms with minimal preparation and no empirical guidance. Practitioners were essentially adapting in real time, making technology-mediated DTT decisions based on clinical judgment alone.

In the broader context of behavior analysis, the scientist-practitioner model obligates clinicians to evaluate the procedures they use. That obligation includes examining whether format modifications — including virtual delivery — alter the functional variables that drive learning. Distance between the clinician and learner affects immediacy of consequence delivery, the clinician's ability to provide physical prompts, and the learner's ability to attend to stimuli. These are not trivial differences and each has measurable bearing on skill acquisition rates. The research presented in this course begins to fill an empirical void that every telehealth-practicing BCBA should understand.

Clinical Implications

The results of this comparative study carry direct implications for how BCBAs structure individualized programs and make decisions about service format. When telehealth delivery produces equivalent outcomes to in-person DTT, this supports expanded access without compromising efficacy. When outcomes differ, practitioners must consider what modifications are needed to close that gap — or whether telehealth is contraindicated for certain learners or skill targets.

Several clinical variables are likely to moderate the telehealth-versus-in-person comparison. Learners who depend on physical prompting will present unique challenges in a virtual context, as gestural and physical prompt hierarchies require physical proximity to implement. Practitioners should conduct a prompt-feasibility analysis before transitioning such learners to telehealth, and caregiver implementation with BCBA observation may be required as a substitute. Error correction procedures may also need modification given latency in virtual environments.

Motivating operations (MOs) play a role as well. The salience of a clinician on a screen is categorically different from in-person presence, which may affect the establishing operation for social reinforcement. For learners whose reinforcer hierarchy is dominated by social attention, this shift in stimulus conditions could reduce reinforcer efficacy and thereby slow acquisition. Practitioners should conduct preference assessments via telehealth and evaluate whether reinforcer hierarchies shift across modalities.

For programs already delivering telehealth, this research informs quality assurance practices. Regular data-based review of acquisition rates — with modality tracked as a variable — allows for early identification of learners who are not responding at expected rates in the virtual context.

Ethical Considerations

The BACB Ethics Code places explicit obligations on practitioners related to service effectiveness and client welfare that are directly relevant to telehealth delivery decisions. Code 2.01 (Providing Effective Treatment) requires that practitioners use evidence-based procedures and measure client progress. When there is reason to believe a procedure is less effective than an available alternative, practitioners are obligated to address that discrepancy. This means telehealth cannot simply be offered because it is convenient — it must be defensible on the basis of outcomes.

Code 2.09 (Treatment Interruption and Discontinuation) and related standards also apply when clients experience plateaus or regressions following a transition to telehealth. If a modality change correlates with a change in learning trajectory, the clinician has an obligation to identify the variable and respond — whether that means reverting to in-person services, modifying the telehealth protocol, or documenting clinical rationale for continuation.

Code 1.05 (Non-Discrimination) introduces an equity dimension. If telehealth is systematically offered to clients based on geography, socioeconomic factors, or other non-clinical considerations, BCBAs must examine whether those decisions are truly in the client's best interest. Offering a potentially inferior service modality to a client because in-person services require longer travel is not automatically unethical, but it requires transparency, informed consent, and ongoing outcome monitoring.

Consent and transparency are codified in Code 2.03. Caregivers and clients have the right to understand what modality of service is being delivered and what the evidence base supports. Documenting the clinical rationale for telehealth delivery, including reference to outcome research, is a best practice that protects both clients and clinicians.

Assessment & Decision-Making

Deciding whether to implement DTT via telehealth, in-person, or a hybrid format requires a structured, data-driven assessment process. The first step is a learner-level analysis that considers the specific skills targeted, the learner's current prompt dependency, history of attending in screen-based contexts, and reinforcer type. Learners who have already acquired foundational attending and instruction-following skills, and who respond well to social reinforcement from familiar adults, are likely better candidates for telehealth DTT than learners who require intensive physical prompting or who have limited screen tolerance.

A setting-level analysis should also be conducted. Telehealth requires a reliable technology setup, a quiet and distraction-controlled environment, and a caregiver who can serve as a trained assistant for in-session tasks. BCBAs should assess these conditions before making telehealth recommendations, and should build in structured training for caregivers who will be proximate to the learner during sessions.

Once telehealth begins, the decision-making framework continues through data review. Practitioners should track trial-by-trial data in the same format used during in-person instruction and compare acquisition rates across modalities where data are available. Visual analysis remains the primary tool for evaluating whether learning is occurring at an acceptable rate.

When data suggest telehealth is less effective for a given learner or program, a stepwise decision process should guide next steps: first, examine implementation fidelity; second, evaluate whether telehealth-specific modifications can address the identified problem; third, consider hybrid models; fourth, consult with supervisors and document all decisions with reference to client outcomes. This evidence-driven process aligns with both the scientist-practitioner model and the BACB Ethics Code.

What This Means for Your Practice

This study equips BCBAs with empirical footing for one of the most consequential logistical decisions practitioners have faced in recent years. Before this kind of comparative research existed, clinicians were making telehealth decisions based on necessity, preference, or incomplete anecdotal evidence. With direct comparison data, the field can move toward principled decision-making frameworks that are grounded in outcomes rather than assumption.

For practitioners currently delivering telehealth DTT, the most actionable takeaway is to treat modality as an independent variable in your data system. If your program software allows you to tag session modality, do so. Then run periodic analyses to compare acquisition rates across conditions for each learner. This is not onerous, but it is the kind of within-case analysis that will tell you far more about your individual clients than group-level research can.

For supervisors, this research reinforces the importance of training staff specifically on telehealth-adapted DTT delivery. Rate of instruction, timing of consequences, and troubleshooting of technology disruptions are all competencies that require explicit training — they cannot be assumed to transfer from in-person DTT skill.

For agencies and clinical directors, this research supports the development of formal telehealth eligibility criteria for DTT programs. These criteria should specify which learner profiles, skill targets, and environmental conditions make a client an appropriate candidate for virtual DTT delivery. Having explicit criteria reduces practitioner-by-practitioner variability and ensures decisions are made on clinical grounds rather than convenience.