The Differential Ability Scales – Second Edition (DAS-II; Elliott, 2007) is an individually administered norm-referenced battery of cognitive subtests for children and adolescents ages 2–6 through 11–17.
Although most cognitive measures are truly language-free, the DAS-II controls for language loading by providing a special Nonverbal Index and can be used easily with very young children and English Language Learners. It consists of two overlapping batteries, the Early Years Battery and the School-Age Battery. Several subtests within each battery can be used out of level for individuals working above or below typical levels by age.
The DAS-II yields (a) a composite score focused on reasoning and conceptual abilities, the General Conceptual Ability (GCA) score; (b) lower-level composite scores called cluster scores; and (c) diverse, specific-ability measures, including the core subtests, which comprise the GCA and diagnostic subtests. Verbal Ability measures the child’s acquired verbal concepts and knowledge. Nonverbal Ability represents complex, nonverbal, inductive reasoning requiring mental processing. Spatial Ability measures complex visual processing. Diagnostic Clusters include Working Memory, Processing Speed, and School Readiness. The DAS-II yields t-scores for subtests and standard scores and percentiles for cluster and index scores and the GCA.
|Author (yr)||Age Range (yrs)||Method of Administration/Format||Approx. Time to Administer||Subscales|
|Differential Ability Scales – Second Edition (DAS-II) Elliott (2007)||2.5-18|| |
Individually administered, norm-referenced measure of cognitive abilities; aligned to the Cattell-Horn-Carroll (CHC) model; 20 subtests (core and diagnostic) in two overlapping batteries: Early Years (2–6 to 3–5 or
|60-90 min.|| |
2–6 to 3–5 yrs.: General Conceptual Ability (GCA) score, Verbal Ability and Nonverbal Ability cluster scores (considered Core Clusters); 3–6 to 11–17: General Conceptual Ability (GCA) score; Verbal Ability, Nonverbal Reasoning Ability, and Spatial Ability cluster scores (Core Clusters); Special Nonverbal Composite; Diagnostic cluster scores (0–5 to 11–17 years) – Working Memory and Processing Speed (0–5 to 8–11 years); School Readiness Cluster
Availability: Pearson Assessment http://bit.ly/1EMmer5
|Author (yr)||Sample Size||Topic(s) Addressed||Outcome|
|Kuriakose (2014)||23 - Age Range: 7-15 (years)||Convergent validity|| |
*Participants achieved significantly higher overall scores on the DAS-II and nearly half the sample achieved a higher classification label on the DAS-II. The difference between overall scores is suggested to be attributable to a relative weakness in processing speed, which is assessed on the WISC-IV but not the DAS-II. Autistic symptomatology was not associated with cognitive scores, while adaptive behavior was positively associated. Neither was associated with the magnitude of difference between overall scores. Choice of assessment should be considered carefully given the systematic differences in overall scores produced in this population.