WAIS FSIQ and GAI Interpretation 3 — Questions and Answers
Question 1: An examinee with ADHD earns an FSIQ of 92 and a GAI of 106. What is the most clinically sound interpretation?
- The FSIQ accurately represents the examinee's intellectual ability
- The GAI better represents core intellectual ability because WMI and PSI are disproportionately affected by ADHD (Correct answer)
- The GAI should be dismissed because it is not a normed composite
- The FSIQ should be reported because it is always the primary score
Correct answer: The GAI better represents core intellectual ability because WMI and PSI are disproportionately affected by ADHD
ADHD often selectively impairs working memory and processing speed, so the GAI may better represent underlying cognitive potential in these cases.
Question 2: On the WAIS-IV normative tables, FSIQ scores between 90 and 109 are classified as:
- High Average
- Average (Correct answer)
- Low Average
- Superior
Correct answer: Average
The Average classification spans FSIQ scores of 90–109 in the WAIS-IV classification system.
Question 3: What is the primary reason the FSIQ may be an underestimate of cognitive ability for an individual with a significant motor speed impairment?
- Processing Speed subtests heavily penalize individuals with motor difficulties, lowering PSI and subsequently FSIQ (Correct answer)
- Verbal comprehension tasks require motor coordination to respond
- Working memory tasks are timed and penalize slow motor responders
- The FSIQ is normed only on individuals without disabilities
Correct answer: Processing Speed subtests heavily penalize individuals with motor difficulties, lowering PSI and subsequently FSIQ
PSI subtests (Coding, Symbol Search) require rapid fine-motor output, so motor impairments artificially suppress PSI and pull down the FSIQ.
Question 4: The confidence interval reported around an FSIQ score is based on which psychometric property of the test?
- The test's validity coefficient
- The standard error of measurement (SEM) (Correct answer)
- The subtest intercorrelation matrix
- The Flynn effect correction factor
Correct answer: The standard error of measurement (SEM)
Confidence intervals are constructed using the SEM, which quantifies the amount of error inherent in any single obtained score.
Question 5: Which index score contributes most heavily to the FSIQ variance in the WAIS-IV factor structure?
- Processing Speed Index
- Working Memory Index
- Verbal Comprehension Index (Correct answer)
- Perceptual Reasoning Index
Correct answer: Verbal Comprehension Index
The VCI has the highest g-loading among the four WAIS-IV indexes and therefore contributes most to FSIQ variance.
Question 6: A psychologist is asked to estimate 'premorbid' intellectual functioning after a traumatic brain injury. Which score is most commonly used as a proxy?
- Processing Speed Index
- Working Memory Index
- FSIQ from the current evaluation
- Word Reading or Vocabulary-based estimate (Correct answer)
Correct answer: Word Reading or Vocabulary-based estimate
Word reading and vocabulary scores are relatively resistant to neurological insult and are commonly used to estimate premorbid IQ.
Question 7: When reporting FSIQ to a non-specialist audience, which descriptor system does the WAIS-IV manual recommend?
- IQ labels from the original 1939 Wechsler-Bellevue scale
- The WAIS-IV qualitative descriptor system (e.g., Average, High Average) (Correct answer)
- DSM-5 severity specifiers (mild, moderate, severe)
- Standard deviation units only, without descriptive labels
Correct answer: The WAIS-IV qualitative descriptor system (e.g., Average, High Average)
The WAIS-IV manual provides a specific qualitative descriptor system that replaces older, stigmatizing labels like 'Borderline Defective.'
WAIS FSIQ and GAI Interpretation 3
An examinee with ADHD earns an FSIQ of 92 and a GAI of 106.
What is the most clinically sound interpretation?