Quiz: Statistical Concepts 

1) IQ scores tend to be fairly stable over time. This is because IQ tests have high:

a) Validity

b) Reliability

c) Measurement error

d) Cultural fairness

2) IQ scores correlate highly with academic performance. This is an example of IQ test:

a) Validity

b) Reliability

c) Discrimination

d) Parallelism

3) Knowing a test’s standard error of measurement tells us:

a) The likelihood of scoring errors

b) How test taker distractibility distorts responses

c) The likelihood that test takers will answer questions incorrectly

d) How many points test scores are likely to vary over time

4) Dr. Hathaway writes the following statement in a test report: “Jennifer’s Verbal Comprehension Index of 102 is slightly higher than her Perceptual Organization Index of 99. This difference reflects slightly stronger verbal than non-verbal skills.” This statement:

a) Accurately describes a significant VCI/POI difference

b) Is inaccurate because the score difference is non-significant

c) Is accurate because the non-significant VCI/POI difference is described as “slight.”

d) Is inaccurate because the VCI is above average, the POI is below average, and thus the difference is not “slight.”

5) Jose’s WRAT-IV Spelling score is significantly higher than his Word Reading score, at a 5% level of significance. This means that:

a) Only 5% of the population has a difference between these scores at least as large as Jose’s

b) There is a 95% chance that Jose’s Spelling score will still be higher than Word Reading if Jose is retested

c) There is a 5% chance that the Spelling/Word Reading difference is due to test error

d) Both b and c 

6) Convert a WAIS-IV IQ (Mean = 100, s = 15) of 95 to a z-score:

a) -0.05

b) -0.33

c) -0.95

d) 6.33

7) A z-score of 0.5 is at what percentile?

a) 25th

b) 50th

c) 69th

d) 84th

8) Abdul obtains a score of 13 on the WAIS-IV Block Design test. If this is the only information that you have, your best estimate of his IQ would be:

a) 87

b) 113

c) 115

d) 130

9) Someone who obtains a T-score of 60 on the MMPI-II Depression scale is scoring higher than what percent of the population?

a) 60%

b) 70%

c) 80%

d) 84%

10) Factor analysis is:

a) A statistical method that shows how variables cluster, based on the correlations between them

b) A modern form of psychoanalysis

c) A way to determine if group means are significantly different

d) A way to draw causal inferences from correlations between variables