By Matt Harrington, BCBA · Behaviorist Book Club · Research-backed answers for behavior analysts
The VB-MAPP (Verbal Behavior Milestones Assessment and Placement Program) is a developmental assessment tool that maps verbal behavior and associated skill development against normative milestones across three levels of complexity. It is designed to assess where a learner falls in the developmental language sequence and to identify appropriate next targets based on that position. The Essential for Living (EFL) is a function-based assessment and curriculum tool that identifies the skills most critical for an individual's safety, independence, and quality of life in their natural environment, without reference to developmental sequence. The VB-MAPP asks 'where is the learner developmentally?' while the EFL asks 'what does this learner most urgently need to do to live safely and independently?'
Key indicators include a significant mismatch between the learner's age or living context and the developmental level of their current programming targets, extended time on developmental targets without progress, critical functional skill deficits in safety, emergency communication, or basic self-care that are not being addressed by the current program, and an approaching transition from school-based services to adult settings where functional independence skills are the primary measure of service success. The decision is not about giving up on developmental progress but about prioritizing the skills that will have the most immediate impact on the learner's quality of life and safety.
Yes, and this is often clinically appropriate. Many learners benefit from continued developmental programming in specific domains where they are making meaningful progress — particularly in early language targets where the developmental sequence provides a principled instructional scaffold — while simultaneously receiving function-based programming for critical life skills that the developmental framework does not address. The practical question is how to allocate instructional time between developmental and functional targets in a way that reflects the learner's priorities. A useful heuristic: any critical EFL skill (safety, emergency communication, essential self-care) should receive instructional time regardless of developmental curriculum demands.
Section 2.01 requires acting in the client's best interest, which means allocating instructional time to the skills most likely to improve quality of life, safety, and independence — not defaulting to a familiar curriculum framework regardless of its fit with the client's current needs. Section 3.01 requires selecting evidence-based treatments appropriate to the client population, which means matching the curriculum framework to the available evidence for that specific client profile. Section 2.11 on client rights includes the right to treatment that genuinely addresses the client's functional needs. Collectively, these sections establish an ethical basis for periodically reviewing whether the current curriculum framework is the right tool for the current client at the current stage of programming.
Start from the family's perspective: what are they hoping their child will gain from ABA programming? Frame the transition in terms of those goals — how function-based programming will build the specific skills the family most wants to see. Provide concrete examples of function-based targets and how they translate into daily life improvements. Acknowledge that this may feel like a shift in expectations, and be explicit that it is not giving up on the child's developmental potential but rather prioritizing the skills that will most immediately improve their quality of life. Present any assessment data that supports the transition recommendation, and give families time and opportunity to ask questions and express concerns.
The EFL identifies 'critical' skills as those whose absence poses the greatest risk to safety, health, or minimum independence in daily life. These include functional emergency communication — the ability to report an emergency or call for help — basic safety skills, essential self-care, and foundational communication for expressing basic needs. These skills are prioritized because their absence creates ongoing vulnerability regardless of where the learner is developmentally. A learner who cannot communicate in an emergency is at genuine risk of harm; this risk is not offset by proficiency in any developmental programming target. The EFL's prioritization framework provides a clinical rationale for protecting instructional time for these skills regardless of other curriculum priorities.
Age is a critical contextual variable in the decision, both because of the relationship between age and the urgency of functional skill development and because of the increasing mismatch between developmental programming targets and age-appropriate life demands as learners get older. Early developmental programming is designed for early language learners — targets that are appropriate at age 4-6 may remain appropriate at age 8-10 for learners with significant developmental differences. By the mid-teens, however, the approaching transition to adult services and the growing importance of community participation, employment preparation, and independence skills shifts the balance toward functional programming. By adulthood, functional independence and quality of life are the primary outcome measures, and developmental milestone attainment is rarely the most meaningful metric.
Staff training for a curriculum transition should include conceptual training on the function-based assessment framework (what the EFL is, how it is organized, and how it differs from developmental assessment), skills training on implementing function-based instructional procedures in natural settings (since many EFL targets are taught in community and daily living contexts rather than structured clinic settings), data collection training for the specific systems used in the new curriculum, and competency verification before independent implementation. Under BACB Ethics Code Section 4.03, the supervising BCBA is responsible for ensuring that staff are competent to implement whatever curriculum is used. A curriculum transition without adequate staff training produces implementation inconsistency that undermines clinical outcomes.
Progress data should be reviewed against both rate of skill acquisition and functional impact. For developmental targets, reviewing the number of skills mastered over a defined period and whether mastered skills are generalizing to natural settings provides a functional effectiveness metric. For function-based targets, the question is whether mastered skills are being used independently in the contexts for which they are targeted. Targets that are mastered in clinical settings but not generalized to natural environments, or developmental targets that have been in acquisition status for extended periods without progress, should prompt a clinical review of whether the current programming approach is appropriate. Data-based curriculum review should occur at least quarterly and whenever a learner's educational or living context changes significantly.
Effective curriculum transitions require applying organizational behavior management principles to the staff behavior change challenge they represent. Antecedent strategies include clearly communicating the clinical rationale for the transition, providing written procedures for new assessment and curriculum implementation, and setting unambiguous performance expectations for the new approach. Training with behavioral skills training (instruction, modeling, rehearsal, feedback) produces better implementation fidelity than didactic training alone. Consequence strategies include specific positive feedback for accurate implementation of new procedures during the early transition period and data-based performance feedback that shows staff the impact of their implementation on client outcomes. Consistent leadership behavior — the supervisor implementing the new approach consistently and enthusiastically — is the single most powerful predictor of successful team adoption.
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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.