Wechsler Test Wechsler Psychometric Properties 2 — Questions and Answers
Question 1: On the WAIS-IV and WISC-V, the Full Scale IQ has a mean of 100 and a standard deviation of what value?
- 10
- 15 (Correct answer)
- 16
- 20
Correct answer: 15
Wechsler scales use a Full Scale IQ mean of 100 and a standard deviation of 15.
Question 2: Individual Wechsler subtest scaled scores are reported on a scale with a mean of 10 and a standard deviation of how much?
- 3 (Correct answer)
- 5
- 10
- 15
Correct answer: 3
Subtest scaled scores have a mean of 10 and a standard deviation of 3.
Question 3: Which type of reliability is most relevant when asking whether a Wechsler subtest yields stable results when the same person is retested weeks later?
- Internal consistency
- Test-retest reliability (Correct answer)
- Inter-rater reliability
- Parallel-forms reliability
Correct answer: Test-retest reliability
Test-retest reliability measures the stability of scores across repeated administrations over time.
Question 4: A correlation between WAIS-IV scores and an independent measure of academic achievement provides evidence of what kind of validity?
- Face validity
- Criterion-related validity (Correct answer)
- Content validity
- Internal consistency
Correct answer: Criterion-related validity
Correlating test scores with an external outcome like achievement reflects criterion-related (concurrent or predictive) validity.
Question 5: What does the Standard Error of Measurement (SEM) primarily help clinicians construct around an obtained Wechsler IQ score?
- A percentile rank
- A confidence interval (Correct answer)
- A scaled score
- A discrepancy score
Correct answer: A confidence interval
The SEM is used to build a confidence interval indicating the range likely to contain the true score.
Question 6: An IQ of 130 on a Wechsler scale (mean 100, SD 15) falls how many standard deviations above the mean?
- 1 SD
- 1.5 SD
- 2 SD (Correct answer)
- 3 SD
Correct answer: 2 SD
130 minus 100 equals 30, which is two standard deviations of 15 above the mean.
Question 7: What is the approximate percentage of the population that scores within the average range (IQ 85-115) on Wechsler scales?
- About 34%
- About 50%
- About 68% (Correct answer)
- About 95%
Correct answer: About 68%
Scores within one SD of the mean (85-115) capture roughly 68% of the population in a normal distribution.
Wechsler Test Wechsler Psychometric Properties 2
On the WAIS-IV and WISC-V, the Full Scale IQ has a mean of 100 and a standard deviation of what value?