WASI-II Wechsler Abbreviated Scale of Intelligence

The WASI-II (Wechsler Abbreviated Scale of Intelligence) is an IQ test for ages 6-90.  It is a shorter and simpler measure based on the more comprehensive Wechsler Intelligence Scale for Children (WISC) and the Wechsler Adult Intelligence Scale (WAIS). 

WASI-II measures cognitive abilities across a range of domains and provides an estimate of a person's general intellectual ability (or Full Scale IQ - FSIQ). It is often used in research studies, and often used to screen for intellectual disability or giftedness, or to assess cognitive abilities in the context of neuropsychological evaluations or clinical diagnoses.

Uses in autistic population

• Assessment of Cognitive Abilities: believed to help identify cognitive strengths and weaknesses in verbal comprehension and perceptual reasoning, which can be informative for planning educational/ behavioral interventions.
• Research: frequently used in autism research studies as measure of cognitive ability.
• Diagnosis: While the WASI-II itself isn't a dx tool for autism, it can be part of a broader diagnostic assessment as it is believed that understanding an individual's cognitive functioning can perhaps provide context for other symptoms or behaviors.

Limitations w.r.t autistic population

• Nonverbal Communication: This test, like many standard IQ tests relies heavily on verbal instructions and responses, particularly in the Vocabulary and Similarities subtests. For autistics who have difficulties with verbal communication or understanding verbal instructions, their scores may not accurately reflect their true cognitive abilities.
• Social Interaction: The testing situation involves 1-1 interaction with the examiner, which could be challenging for autistics due to difficulties with social interaction and maintaining eye contact (eg: repeated demands of "look at me" and "quiet hands" that are often stressful). The unfamiliar environment and interaction may add an extra layer of stress and influence their performance on the test.
• Specific Skills: It does not evaluate all areas of cognitive functioning. It provides an overview of verbal comprehension and perceptual reasoning but does not assess areas such as working memory and processing speed. Additionally, it does not assess adaptive functioning, executive functioning, or other cognitive skills that may be areas of difficulty for autistics
• Cognitive Profile Variability: Autistics often have uneven cognitive profiles with peaks and valleys in different areas of cognitive functioning. The brevity of WASI-II and its focus on only a few areas of cognition, might not capture this variability.
• also SEE POST on why IQ testing is problematic for autistics

The WASI-II has four subtests

Vocabulary, Similarities, Block Design, and Matrix Reasoning. These are intended to measure verbal comprehension and perceptual reasoning abilities.

• Vocabulary measures word knowledge and verbal concept formation.
• Similarities measures verbal concept formation and reasoning.
• Block Design measures spatial processing and visual-motor integration.
• Matrix Reasoning measures nonverbal fluid reasoning and general intellectual ability.

Scores from these subtests can be combined to create the FSIQ. Two-subtest (Vocabulary and Matrix Reasoning) and three-subtest versions (adding Block Design) are also used depending on the assessment needs.

History

Developed by psychologist David Wechsler (2nd edition 2011, First Ed in 1999).