In the IDS-2, cognitive ability is measured by both the Intelligence Domain and the Executive Functions Domain.
The IDS-2 approach to intelligence uses the Cattell-Horn-Carroll theory of hierarchical intelligence (CHC theory; McGrew, 1997). CHC theory describes the structure of intelligence as being rooted in different dimensions, and performances within these dimensions are measured with a selection of performances variables, or tasks. Using a variety of these types of tasks, the IDS-2 can assess the tools the child or adolescent has at their disposal to acquire knowledge - instead of only looking at the knowledge that they have already acquired.
There are three scores available: IQ-Screening looks at a verbal and a nonverbal component; IQ measures seven factors (visual processing, long-term memory, processing speed, auditory short-term memory, visual spatial short-term memory, abstract reasoning and verbal reasoning); and IQ-Profile measures each factor twice, with different tasks inside the subtests.
Executive functions are regulation and control processes that enable goal-oriented and situational action. The three basic mechanisms are inhibition, working memory and cognitive flexibility, which can display a developmental growth beyond preschool and school age into adolescence and early adulthood.
In preschool children, executive functions are connected to language ability, fluid intelligence, motor coordination ability, and the ability to self-regulate. Thus, they are significant in the context of developmental requirements for school readiness and school success.
Tests include asking children to perform single tasks (e.g. listing words) as well as multiple tasks, both verbal and nonverbal.
