Wechsler Psychometric Properties Questions and Answers

Question 1

The Full Scale IQ (FSIQ) of the WAIS-IV has an average internal consistency reliability coefficient of .98. What does this high coefficient primarily indicate?

Accepted Answer

The test items consistently measure the same underlying construct.

Answer

Internal consistency reliability (often measured by Cronbach's alpha or split-half reliability) refers to the degree to which different items on a test that propose to measure the same general construct produce similar scores. [5] A high coefficient like .98 indicates that the items are highly interrelated and consistently measuring the same thing (in this case, general intellectual ability). [3, 5]

Question 2

A school psychologist finds that a student's WISC-V FSIQ score is highly correlated with their scores on a nationally standardized achievement test administered during the same week. This finding provides strong evidence for the WISC-V's:

Accepted Answer

Concurrent validity

Answer

Concurrent validity, a form of criterion-related validity, is demonstrated when scores from a test are significantly correlated with scores from a relevant, established measure administered at approximately the same time. The strong correlation between the WISC-V (an intelligence test) and an achievement test supports the idea that the WISC-V is measuring cognitive abilities related to current academic performance. [24, 33]

Question 3

An examiner calculates a 95% confidence interval of [104, 116] for an examinee's Verbal Comprehension Index (VCI) score of 110. The width of this interval is directly determined by the:

Accepted Answer

Standard error of measurement (SEM) for the VCI.

Answer

A confidence interval is constructed around an obtained score to estimate the range within which the individual's 'true' score likely falls. This range is calculated using the standard error of measurement (SEM), which quantifies the amount of error inherent in any test score. A larger SEM results in a wider confidence interval, and a smaller SEM results in a narrower one. [4, 8, 10]

Question 4

Which of the following is the most critical feature of the standardization sample used to develop the norms for a Wechsler intelligence scale?

Accepted Answer

It must be representative of the general population on key demographic variables.

Answer

The primary goal of a standardization sample is to be representative of the population for whom the test is intended. This is achieved by stratifying the sample based on key demographic variables like age, sex, race/ethnicity, geographic region, and parent education level, matching recent census data. [21, 27, 28] This representativeness allows for meaningful comparison of an individual's score to their peers.

Question 5

Test developers regularly update and re-standardize the Wechsler scales. A primary psychometric reason for this is to counteract the 'Flynn effect,' which refers to the observed phenomenon of:

Accepted Answer

The rising scores of the population on intelligence tests over generations.

Answer

The Flynn effect is the well-documented, long-term trend of rising scores on intelligence tests in many parts of the world. [1, 2, 9] To ensure that an IQ score of 100 continues to represent the average performance of the current population, tests must be periodically re-normed on a new, contemporary standardization sample. Using outdated norms would result in artificially inflated scores. [14]

Wechsler Test Practice Test

Wechsler Test Practice Test

Wechsler Psychometric Properties Questions and Answers