What is the VB-MAPP? The verbal behavior assessment explained

The Verbal Behavior Milestones Assessment and Placement Program, better known as the VB-MAPP, is a skills assessment, curriculum guide, and skill-tracking system for children with autism and other individuals who show language delays. It is used inside "applied behavior analysis" (ABA) programs and special-education classrooms to map which language and social skills a child currently has and to guide what gets taught next. The VB-MAPP is not an IQ test, and it is not a diagnostic instrument. It produces no intelligence score, and it cannot determine whether a child has autism; diagnosis belongs to qualified clinicians using clinical interviews, observation, and their professional judgment. Written by behavior analyst Mark L. Sundberg and published by AVB Press in 2008, the VB-MAPP is one of the most widely used tools of its kind. This article explains what it measures, how its five components fit together, and how it differs from a test of intelligence.

Sundberg describes the VB-MAPP as a "criterion-referenced" assessment, meaning a child's performance is compared against a fixed list of skills rather than against the scores of other children. That is a fundamental difference from IQ tests and most standardized language tests, which are "norm-referenced" and report how far a score sits above or below the average for the child's age group. A criterion-referenced tool answers a different question: which specific skills can this child demonstrate today?

The skill list itself comes from B.F. Skinner's 1957 book Verbal Behavior, which analyzed language by its function. In Skinner's system, a "mand" is a request driven by what the speaker wants, a "tact" is a label for something the speaker sees or hears, an "echoic" is a repetition of what someone else said, and an "intraverbal" is a verbal response to someone else's words, such as answering a question. Sundberg states that the VB-MAPP is built on this analysis along with established developmental milestones and research from behavior analysis.

The program has a long development history. Sundberg began building verbal behavior assessments in the 1970s as a graduate student of Dr. Jack Michael at Western Michigan University, and a 1998 predecessor developed with Dr. James W. Partington was published as the ABLLS. The VB-MAPP followed in 2008 after field testing by behavior analysts, speech pathologists, teachers, and parents across the United States and Canada.

According to Sundberg's official description, the VB-MAPP contains five components that together establish a baseline, point toward intervention targets, and track progress over time.

• Milestones Assessment: the core of the program, with 170 measurable milestones sequenced across three developmental levels that correspond to typical development from 0 to 18 months, 18 to 30 months, and 30 to 48 months. The milestones cover manding, tacting, echoic skills, intraverbals, listener skills, motor imitation, independent play, social skills, visual perception and matching-to-sample, linguistic structure, group and classroom skills, and early academics. An Early Echoic Skills Assessment developed by speech pathologist Dr. Barbara E. Esch is included as a subtest.

• Barriers Assessment: an evaluation of 24 common obstacles to learning and language acquisition, including behavior problems, weak instructional control, defective mands or tacts, prompt dependency, rote responding patterns such as "scrolling" (emitting a chain of guesses), and failure to generalize skills to new settings.

• Transition Assessment: 18 measures that help an IEP team judge whether a child is making meaningful progress and has the skills needed to learn in a less restrictive educational setting, drawing on summary scores from the other assessments plus skills such as adaptability to change and independent work.

• Task Analysis and Supporting Skills: 35 pages in the scoring protocol that break skills down further, covering 14 of the 16 milestone domains with hundreds of smaller steps and supplementary skills. The publisher reports over 700 supporting skills in total.

• Placement and IEP Goals: specific placement guidance for each of the 170 milestones along with suggested goals, intended to help program designers build a balanced individualized curriculum.

Conducting the assessment requires two documents from the publisher. The VB-MAPP Guide contains the administration instructions, scoring criteria, charting instructions, and IEP goal suggestions, and one Guide can be reused across children. The VB-MAPP Protocol contains the actual scoring forms and charts, and each child needs an individual copy. AVB Press notes that a single Protocol is designed to record and chart a child's skill acquisition over several years, so repeated administrations fill in a visual grid that shows growth across the three levels.

The tool is written to be usable by a range of professionals, but the publisher is direct about prerequisites. According to the AVB Press FAQ, a tester needs a basic understanding of Skinner's analysis of verbal behavior, knowledge of behavior analysis fundamentals such as prompting, familiarity with basic linguistic structure and typical language development, and a good understanding of autism and other intellectual disabilities. In practice the VB-MAPP is commonly administered by Board Certified Behavior Analysts, speech-language pathologists, psychologists, and trained special-education staff.

The program has spread well beyond English-speaking classrooms. The publisher reports that the VB-MAPP is currently available in 12 languages, with more translations underway, and an authorized app version built with the company Data Makes the Difference allows electronic scoring and charting.

Because the VB-MAPP is criterion-referenced, it has no norm sample and no standard scores, so its psychometric evidence looks different from that of an IQ test. The most direct reliability evidence comes from a 2019 study in the Journal of Autism and Developmental Disorders by Montallana and colleagues, who had pairs of raters independently assess 32 children with autism. The "intraclass correlation," a statistic that reflects how closely two raters' scores agree, was 0.876 for the total Milestones score, which the authors describe as good reliability, and 0.629 for the total Barriers score, which is moderate. Agreement for many individual domains was weaker, and the authors caution that high reliability for individual domains should not be assumed. They also note theirs were the first published reliability data for the instrument, a striking gap for a tool released in 2008.

Administration quality depends heavily on training. A 2014 study by Barnes, Mellor, and Rehfeldt in The Analysis of Verbal Behavior found that school psychologists who only read the manual averaged 57 percent accuracy on an administration checklist, while structured behavior skills training with modeling, rehearsal, and feedback raised average accuracy to 92 percent. The practical lesson for parents is worth stating plainly: VB-MAPP results are most meaningful when the assessor is properly trained, and results from an untrained administration should be interpreted cautiously.

An IQ test estimates general cognitive ability and reports standardized scores on a scale with a mean of 100 and a "standard deviation," a measure of score spread, of 15 points. The VB-MAPP does none of this. It inventories specific language, social, and learning skills against developmental levels that top out around the 48-month mark of typical development, which makes it informative for early intervention planning and uninformative as a measure of intelligence. It also differs from adaptive behavior scales such as the one described in our article on the ABAS-3, which rate everyday functioning across the lifespan, and from diagnostic observation tools such as the ADOS-2, which trained clinicians use as part of an autism evaluation. Readers interested in how cognitive ability testing intersects with autism can find a fuller discussion in our article on IQ and autism.

For adults who want a rigorous measure of cognitive ability, the RIOT IQ test (the Reasoning and Intelligence Online Test) serves a different population and purpose entirely. Developed by RIOT IQ with psychometrician Dr. Russell T. Warne for adults 18 and older, it includes 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time), takes about 52 minutes, and reports scores on the familiar mean-100, standard-deviation-15 scale. Like any online measure, it does not replace an individually administered diagnostic evaluation. You can take the RIOT IQ test at riotiq.com.

No. The VB-MAPP is a criterion-referenced skills assessment and curriculum-planning tool. It does not measure general intelligence and does not produce an IQ score.

No. It assesses language and related skills to guide teaching. Autism diagnosis requires a qualified clinician using dedicated diagnostic procedures.

Its milestones correspond to typical development from birth to 48 months. Children assessed with it are often chronologically older; the levels describe skill development rather than age.

Anyone conducting it should understand Skinner's analysis of verbal behavior, basic behavior analysis, and typical language development. It is most often administered by behavior analysts, speech-language pathologists, psychologists, and trained educators.

The first published study found good rater agreement for the total Milestones score and moderate agreement for the Barriers score, with weaker agreement in many individual domains, so domain-level results deserve caution.

Yes. The publisher reports 12 language versions and an authorized app for electronic scoring and progress charting.

1. AVB Press. (n.d.). AVB Press: Official VB-MAPP publisher. avbpress.com

2. AVB Press. (n.d.). Frequently asked questions. avbpress.com

3. Barnes, C. S., Mellor, J. R., & Rehfeldt, R. A. (2014). Implementing the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP): Teaching assessment techniques. The Analysis of Verbal Behavior, 30, 36-47. pmc.ncbi.nlm.nih.gov

4. Montallana, K. L., Gard, B. M., Lotfizadeh, A. D., & Poling, A. (2019). Inter-rater agreement for the Milestones and Barriers Assessments of the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP). Journal of Autism and Developmental Disorders. doi.org

5. Sundberg, M. L. (n.d.). VB-MAPP. Mark Sundberg official site. marksundberg.com

6. Sundberg, M. L. (2008). Verbal behavior milestones assessment and placement program: The VB-MAPP. AVB Press. avbpress.com

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