Differential Ability Scales
The Differential Ability Scales is a nationally normed, and individually administered battery of cognitive and achievement tests. Currently into its second edition, 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, 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.