Differential Ability Scales
The Differential Ability Scales (DAS) is a nationally normed (in the US), and individually administered battery of cognitive and achievement tests. Currently into its second edition (DAS-II) the test can be administered to children ages 2 years 6 months to 17 years 11 months across a 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.
The original DAS was developed from the BAS British Ability Scales both by Colin D. Elliot and published by Harcourt Assessment in 1990.
Test Structure
The DAS-II consists of 20 cognitive subtests which include 17 subtests from the original DAS.
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.
| Core Cognitive Tests | Diagnostic Tests |
|---|---|
| Pattern construction | Recall of designs |
| Word definitions | Recognition of pictures |
| Similarities | Recall of objects |
| Matrices | Speed of information processing |
| Sequential & quantitative reasoning | |
| Recall of design |
Ages 6-17 only
Early Years Cognitive Battery
The Early Years core battery includes verbal, nonverbal, and spatial reasoning subtests appropriate for ages 2 years 6 months to 6 years 11 months.
There are three optional diagnostic subtests - Recall of Objects Immediate and Delayed, Recall of Digits Forward, and Recognition of Pictures. There are also two optional diagnostic clusters: working memory and processing speed.
School-Age Cognitive Battery
The School-Age core battery contains subtests that can be used to assess children ages 7 years to 17 years 11 months. These subtests measure verbal, nonverbal reasoning, and spatial reasoning abilities. The subtests can also be used to assess children ages 5 years to 6 years 11 months 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.
References
- Pearson Clinical. Differential Ability Scales-II (DAS-II) Product Page.
- Harcourt Assessment. Differential Ability Scales-II (DAS-II) Product Page. .
Further reading
- Daniel, Mark H. (1995). "Differential Ability Scales". In Sternberg, Robert J. Encyclopedia of human intelligence. 1. Macmillan. pp. 350–354. ISBN 978-0-02-897407-1. OCLC 29594474.
- Elliott, Colin D. (2012). "Chapter 13: The Differential Ability Scales—Second Edition". In Flanagan, Dawn P.; Harrison, Patti L. Contemporary Intellectual Assessment: Theories, tests, and issues (Third ed.). New York (NY): Guilford Press. pp. 336–356. ISBN 978-1-60918-995-2. Lay summary (29 March 2014).
- Urbina, Susana (2004). Essentials of Psychological Testing. John Wiley & Sons. ISBN 9780471679011. Lay summary (10 October 2013).
- Urbina, Susana (2011). "Chapter 2: Tests of Intelligence". In Sternberg, Robert J.; Kaufman, Scott Barry. The Cambridge Handbook of Intelligence. Cambridge: Cambridge University Press. pp. 20–38. ISBN 9780521739115. Lay summary (9 February 2012).