Wide Range Achievement Test Wide Range Achievement Psychometric Properties 3 — Questions and Answers
Question 1: On the WRAT-5, which statistical index directly quantifies the amount of error in a single observed score?
- Coefficient alpha
- Standard error of measurement (SEM) (Correct answer)
- Standard deviation of the norm group
- Correlation coefficient with a criterion
Correct answer: Standard error of measurement (SEM)
The standard error of measurement (SEM) directly quantifies the expected amount of error in a single observed score.
Question 2: Which factor would most likely inflate WRAT-5 test-retest reliability coefficients artificially?
- A long retest interval of 6 months
- Memory for specific items from the first administration (Correct answer)
- Variability in examiner administration
- Changes in the examinee's true ability
Correct answer: Memory for specific items from the first administration
A short retest interval allows examinees to remember specific items, inflating stability coefficients beyond what true ability consistency would produce.
Question 3: The WRAT-5 composite score combining all four subtests is best described as which type of score?
- A factor score derived from confirmatory factor analysis
- A simple mean of subtest raw scores
- A composite standard score averaged from individual subtest standard scores (Correct answer)
- A percentile rank averaged across subtests
Correct answer: A composite standard score averaged from individual subtest standard scores
The WRAT-5 composite is derived by averaging the standard scores of individual subtests and converting that average to an overall composite standard score.
Question 4: According to WRAT-5 psychometric guidelines, which minimum reliability coefficient is generally considered acceptable for making high-stakes individual decisions?
- .70
- .80
- .90 (Correct answer)
- .95
Correct answer: .90
A reliability coefficient of .90 or higher is the widely accepted minimum threshold for tests used in high-stakes individual decision-making.
Question 5: Which type of score transformation preserves the exact rank order of raw scores and is used to create WRAT-5 percentile ranks?
- Linear transformation
- Nonlinear normalization (Correct answer)
- Ordinal ranking without transformation
- Logarithmic compression
Correct answer: Nonlinear normalization
Percentile ranks are derived through nonlinear normalization that maps raw scores onto a cumulative frequency distribution, preserving rank order while adjusting for distributional shape.
Question 6: Which WRAT-5 feature allows clinicians to evaluate whether observed score differences between subtests are statistically meaningful versus due to chance?
- Percentile rank tables
- Significance tables for pairwise subtest score differences (Correct answer)
- Confidence interval charts
- Age-equivalent score conversions
Correct answer: Significance tables for pairwise subtest score differences
Significance tables for pairwise subtest score differences allow clinicians to determine whether a difference between two subtest scores exceeds what would be expected by chance.
Question 7: A student scores at the 16th percentile on WRAT-5 Spelling. Approximately what standard score does this correspond to?
- 70
- 85 (Correct answer)
- 90
- 115
Correct answer: 85
The 16th percentile corresponds to approximately one standard deviation below the mean, which equals a standard score of 85 on a scale with mean=100 and SD=15.
Wide Range Achievement Test Wide Range Achievement Psychometric Properties 3
On the WRAT-5, which statistical index directly quantifies the amount of error in a single observed score?