Adaptive Behavior Assessment System, Second Edition (ABAS-II) Revised

Adaptive Behavior Assessment System, Second Edition (ABAS-II) Revised

Adaptive Behavior Assessment System, Second Edition (ABAS-II) Revised

Name Adaptive Behavior Assessment System, Second Edition (ABAS-II) Revised

To assess adaptive skills across the life span i.e practical independent functioning and the effectiveness of interactions with others and include consideration of community and cultural contexts.

Population 0 to 89 years

The ABAS-II includes 10 skill area scores (Communication, Community Use, Functional Academics, Health and Safety, Home or School Living, Leisure, Self-Care, Self-Direction, Social, and Work )

Time 15-20 minutes
Author Patti L. Harrison, PhD, and Thomas Oakland, PhD
Publisher The Psychological Corporation

 The Adaptive Behavior Assessment System – Second Edition (ABAS-II,2003) is a revision and downward extension of Harrison and Oakland’s Adaptive Behavior Assessment System (2000). It was developed for diagnosing and classifying various developmental, learning, and behavioral disabilities and disorders; identifying clients’ strengths and weaknesses; and documenting and monitoring progress over time.


 The ABAS-II includes 10 skill area scores (Communication, Community Use, Functional Academics, Health and Safety, Home or School Living, Leisure, Self-Care, Self-Direction, Social, and Work). Motor skill area scores are available on the two forms appropriate for children up to age 5 years. The ABAS-II has four domain composite scores (Conceptual, Social, Practical, and General Adaptive Composite or GAC). Communication, Functional Academics, and Self-Direction skill areas comprise the Conceptual domain. Social and Leisure skill scores combine to make the Social domain. Self-Care, Home or School Living, Community Use, Health and Safety, and Work comprise the Practical domain. The Work skill area is optional for adults and for youth of working age, while a Motor skill area for young children, but it is not part of any of the domain scores. The General Adaptive Composite and domain composite scores have a mean of 100 and a standard deviation of 15. Skill area standard scores have a mean of 10 and a standard deviation of 3. Age-based percentile ranks and test-age equivalents are included up to the test age of 22 years.


Most of the skill area showed high internal consistency coefficients i.e .90 or greater. The average internal consistency coefficient for the standardization sample’s GAC ranges from .98 to .99. Also test-retest reliabilities by age group for each of the ABAS-II forms as well as for the various scores. Sample sizes were from 30 to 207. GAC correlations were mostly above or near .90 for teacher, parent, and adult forms.


ABAS-II is consistent with  American Association of Mental Retardation recommendations 1992 and 2002 standards as well as state and federal mandates and the DSM-IV-TR .

The construct validity of the ABAS-II is also supported by intercorrelational data among the skill areas, domains, and the GAC. The theoretical structure of the ABAS-II gains support from the average correlations found on the different rating forms among the 10 skill areas. These correlations are in the moderate range (.40s to .70s). Correlations between the skill areas and their adaptive domains (.55 to .78), the skill areas and the GAC (.64 to .82), and the adaptive domains and the GAC (.78 to .93) are consistent with the model of adaptive behavior presented in the ABAS-II. A number of studies reported concurrent validity, and studies show correlations between the Adaptive Behavior Composite on the Vineland Adaptive Behavior Scale and the GAC for three different non-clinical samples (n = 44, 59, 45). Studies showed correlations between the ABAS-II and the SIB-R, Behavior Assessment Scale for Children (BASC). The negative correlations indicated between the GAC and the BASC scales for Externalizing Problems was -.49. The correlation was -.39 for Internalizing Problems and -.66 for the Behavior Symptoms Index.

A number of different studies with sample sizes ranging from 19 to 306 revealed correlations in the .40s and .50s between the ABAS-II and various measures of intelligence (e.g., WPPSI-III, WAIS-III, WISC-IV) and achievement (e.g., WASI, WIAT). Scores on the ABAS-II from participants with learning disabilities, ADHD, hearing impairments, mental retardation, and developmental delay were matched based on demographic characteristics with members of the standardization sample.


 The total sample was based on United States census data from 1999 (School and Adult forms) and 2000 (Infant and Preschool forms). There were 31 separate age groups assessed using the Infant-Preschool, School Age, and Adult forms. There were at least 100 participants in each group. The largest sample was for the 13- to 14-year-old children using the Teacher form. There were 250 participants in that group. It also included 20 clinical samples (e.g., ADHD, autistic disorder, and visual impairment).

Suggested Uses

 ABAS II is recommended for a wide variety of population including clinical, educational, work and research . Particularly useful for evaluating those with developmental delays, autism spectrum disorder, intellectual disability, learning disabilities, neuropsychological disorders, and sensory or physical impairments. Integrates assessment, intervention planning, and progress monitoring

Prepared by

Lubna Ghazanfar

November 10, 2015 / by / in ,
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