The Differential Ability Scales (DAS) is a nationally normed (in the US), and individually administered battery of
cognitive
Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought ...
and achievement tests. 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
The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight ...
working memory
Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term 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
Harcourt Assessment was a company that published and distributed educational and psychological assessment tools and therapy resources and provided educational assessment and data management services for national, state, district and local assessme ...
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.
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 8 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.
Uses for assessing giftedness
Both DAS editions are suitable for evaluation of
intellectual giftedness
Intellectual giftedness is an intellectual ability significantly higher than average. It is a characteristic of children, variously defined, that motivates differences in school programming. It is thought to persist as a trait into adult life, wi ...
, and high scores are accepted as qualifying evidence for
high IQ societies such as
Intertel
Intertel (previously the International Legion of Intelligence) is a high-IQ society founded in 1966, that is open to those who have scored at or above the 99th percentile (top 1%) on one of various standardized tests of intelligence. It has been ...
(min. GCA 135 on DAS-II) and
American Mensa
Mensa is the largest and oldest high-IQ society in the world. It is a non-profit organisation open to people who score at the 98th percentile or higher on a standardised, supervised IQ or other approved intelligence test. Mensa formally compr ...
(min. GCA 130 on DAS-II).
References
*Pearson Clinical
Differential Ability Scales-II (DAS-II) Product Page
*Harcourt Assessment
.
Further reading
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Cognitive tests
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Intelligence tests