Differential Ability Scales-II (DAS-II) US Version

Overview:  Using profile analysis, you can identify the child’s strengths and weaknesses, so the appropriate IEP goals, intervention strategies, and progress monitoring can be developed

Qualification Level: C

Age Range:  2:6 – 17:11 years

RTI Tiers: RTI Level 3

Administration:  Paper-and-pencil

Completion Time:  Core Battery 45-60 minutes; Diagnostic Subtests 30 minutes

Scores/Interpretation:  Standard Scores and Percentiles by age

The design of Differential Ability Scales–Second Edition (DAS-II) comes out of a vision to provide the psychologist with insight into how a child processes information to devise appropriate interventions and/or recommendations for the classroom and at home.

The DAS–II is a comprehensive, individually administered, clinical instrument for assessing the cognitive abilities that are important to learning. The test may be administered to children ages 2 years 6 months (2:6) through 17 years 11 months (17:11) across a broad range of developmental levels.

The diagnostic subtests measure a variety of cognitive abilities including verbal and visual working memory, immediate and delayed recall, visual recognition and matching, processing and naming speed, phonological processing, and understanding of basic number concepts. Some of these subtests can be used with children ages 2:6–17:11, while others have specific age ranges.

“DAS-II helps you find out why a child isn’t learning, and targets the specific nature of the problem, so that appropriate intervention strategies can be identified. It’s a well-rounded assessment of a child’s strengths and ability that also enables measuring change over time, in order to monitor progress.”
Dr. Colin Elliott, DAS-II author

Features & Benefits

The Differential Ability Scales ® –Second Edition (DAS–II) continues the tradition of providing an in-depth analysis of children’s learning abilities. Using profile analysis, you can identify the child’s strengths and weaknesses so the appropriate IEP goals, intervention strategies, and progress monitoring can be developed. The DAS-II is appropriate for diverse populations as it can predict achievement on the basis of ability equally well for African American, Asian, Hispanic, and White/Non-Hispanic children. More information about the cultural fairness of DAS-II is available in the Technical Manual.

The DAS-II covers all ability levels for ages 2:6 – 17:11 split into two battery levels. For ages 5:0 – 8:11, both levels of the battery are fully co-normed, allowing the examiner to use subtests from either level of the battery, depending upon the child’s performance on the age-appropriate subtest. Additionally, the examiner can compare performance on the subtests tapping similar constructs from each battery to test hypotheses about the reasons for high or low scores. With DAS-II’s age range of 2:6-17:11 years, you can complete comparisons of test performance across time – even when normative scores cannot be obtained for a child of a given age, ability scores can be compared across time.

Product Features

DAS-II is Theoretically Driven

• All major CHC broad abilities are represented in the DAS-II subtests and composites.
   
• Subtests map onto neuropsychological constructs, and reflect recent research in working memory and reading acquisition. Each subtest measures a homogeneous, reliable, and distinct set of cognitive abilities allowing clinicians the flexibility to use the test piecemeal with confidence.
   
• DAS-II uses state-of–the-art psychometric techniques that make the instrument time-efficient, yet produce the highest reliable subtest specificity of any cognitive battery. The result is effective profile analysis of an individual’s strengths and weaknesses in cognitive processing.
   
• Rasch modeling was applied to the construction of item sets to ensure ability levels were appropriate within each battery, resulting in only having to administer the items necessary to achieve a sufficient work sample, on a reliable subset of items. This efficiency helps children from experiencing boredom or fatigue by items that are either too easy or hard to reliably discriminate among age mates.

DAS-II is Child-Friendly

• Increased floor for all subtests allows all children to find success on at least a few items, providing clinicians an understanding of what a child can do while preserving the rapport with the child.
   
• Contains an abundance of teaching items to ensure a child does not fail because the instructions were not understood clearly.
   
• Presents a wide range of engaging, child-appropriate activities to elicit optimal performance and create a positive view of testing in general.
   
• Offers administration flexibility through out of level testing options with extended General Conceptual Ability (GCA) and cluster scores available for children experiencing cognitive delays.
   
• Offers Spanish translation and American Sign Language translation of the nonverbal subtest administration instructions.
   
• Tailored testing procedures reduce overall administration time, make maximum use of the child’s energy, and facilitate rapport.

 
What’s New with DAS-II

The original DAS has provided the strong cognitive foundations for the DAS-II. The revision has gone even further in translating cognitive development and cognitive process research findings into easily administered and interpreted subtests. The 20 cognitive subtests of the DAS-II include 17 subtests from the original DAS. The subtests are divided into two batteries based on age and are further subdivided into core and diagnostic subtests. Here are some of the new features:

• Updated normative sample representative of the general U.S. population
   
• New items and four new subtests—Recall of Sequential Order, Rapid Naming, Phonological Processing and Recall of Digits–Backward
   
• Block Building subtest is combined with the Pattern Construction subtest
   
• Matrices subtest now contains a set of items for young children
   
• Expanded clinical samples of children with a variety of special classifications (i.e., developmental risk; reading, writing, and math learning disabilities; attention-deficit/hyperactivity disorders; specific language impairment; limited English proficiency; mild to moderate intellectual disability; and gifted and talented)
   
• More engaging and contemporary artwork
   
• Modified the administration and scoring procedures to enhance the user-friendliness of the scale
   
• Spanish language translation of the nonverbal subtests
   
• CD with examiner instructions to assist with administration of the phonological processing subtest, and signed nonverbal subtest administration directions (signed sentences)
   
• Linked to WIAT-III to tap into all areas of disability, as specified in IDEA 2004

 
Test Structure

The diverse nature and individual reliability of the core and diagnostic subtests make the DAS–II a useful tool for profiling a child’s strengths and weaknesses. All 20 subtests involve activities that are appropriate to the developmental level of every child. The subtests are grouped into the Early Years and School-Age cognitive batteries with subtests that are common to both batteries and those that are unique to each battery. These batteries provide the General Conceptual Ability score (GCA), which is a composite score focusing on reasoning and conceptual abilities.

Early Years Cognitive Battery

The Early Years core battery includes verbal, nonverbal, and spatial reasoning subtests appropriate for ages 2:6 through 6:11. The battery is divided into two levels: children ages 2:6–3:5 and 3:6–6:11. The younger children are administered four core subtests to obtain the GCA composite score and children ages 3:6–6:11 take six core subtests which contribute to the GCA composite score. Although these subtests focus on ages 2:6-6:11, it can also be used to assess children ages 7:0–8:11 who are suspected of having cognitive delay.

There are eleven optional diagnostic subtests for this age group. There are also three optional diagnostic clusters: Working Memory, Processing Speed, and School Readiness.

School-Age Cognitive Battery

The School-Age core battery contains subtests that can reliably be used to assess children ages 7:0 through 17:11. These subtests measure verbal, nonverbal reasoning, and spatial reasoning abilities. The subtests can also be used to assess children ages 5:0–6:11 who may be cognitively gifted. In addition there are up to nine diagnostic subtests for this age group that feed into three possible diagnostic cluster scores: working memory, processing speed and, for the youngest ages, school readiness.

 
Out of Level Testing for those children at the extremes of ability ranges

As the clinician there are times when you might not know exactly who you are going to be testing on a given day, in a given school. The DAS-II offers you flexibility in being able to tailor the test based on the empirical observations you make about the child—from children with very low ability to children with giftedness. You can feel confident in your decision even when the test is tallied as the child will still be compared to a reference group of age mates – because all of these subtests were normed for his or her age mates.

The Early Years and School-Age batteries were normed for overlapping age ranges, and both were standardized with children ages 5:0–8:11. This overlap permits out-of-level testing and insures that bright, younger children and less able older children can be given subtests appropriate for their abilities. Gifted children have the opportunity to show just how much they can do, by taking subtests typically administered to older children. Children of very low ability also have the opportunity to demonstrate what they can do, through administering the appropriate DAS-II subtests.

In analyzing the normative information, two decisions were made to simplify the normative data tables. For all remaining ages outside the age range of 5:0-8:11 years, all subtests have sufficient floors and ceilings, except where explicitly indicated (by shading in the norms manuals). When a subtest is not reliable for a particular age, it is because the ability being measured is developmentally inappropriate for almost all children of that age. The subtest and cluster/composite standard scales were extending to four standard deviations on either side of the mean for each age band. This means the GCA goes down to 30, up to 170; and subtests go from T=10 to T=90.

There may be instances were you have a child of age 9 years or older who is unable to provide a sufficient work sample for the School Age battery. The DAS-II offers extended GCA, SNC and all cluster scores via backchannel. These extended norms will not provide much of a downward extension in terms of standard scores (only down to 25 as opposed to 30); however, they will allow a child of this ability to be tested using subtests on which they will find some success, and still be compared against the projected performance of their actual age-mates.

Offering this combination of scores makes the DAS–II useful for classifications and placement decisions that require an index of intellectual ability, for diagnostic testing that may contribute to understanding a child’s weaknesses and strengths, and for designing tailored interventions.

 
Clinical and Validity Studies

Clinical Studies

• Developmental Risk
   
• Intellectual Disability, including children with Down Syndrome
   
• Learning Disorder in Reading
   
• Learning Disorder in Reading and Writing
   
• Learning Disorder in Math
   
• Expressive Language Disorder
   
• Mixed Receptive/Expressive Language Disorder
   
• ADHD and a combination of Learning Disabilities (Reading , Writing, Math)
   
• ADHD
   
• Limited English Proficiency
   
• Deaf and Hard of Hearing

Validity Studies—Establishing Lines of Validity Evidence Cognitive Ability

• Bayley Scales of Infant Development–Second Edition
   
• WISC–IV
   
• WPPSI–III

Achievement

• WIAT–III
   
• KTEA-II – Kaufman Test of Educational Achievement Second Edition
   
• Woodcock Johnson- III

Emerging Skills

• Bracken School Readiness
   
• Ready to Learn

DAS-II Comprehensive Kit #015833969X
Includes Administration Manual, Technical Manual, Normative Data Tables, 15 Preschool Record Forms, 15 School-age Record Forms, 10 each of Speed of Information Processing Booklets Versions A, B, and C, 4 Stimulus Books, Object Recall Card, Picture Similarities Cards, Phonological Process and Signed Sentences CD, and Manipulatives, and Scoring Assistant