CRS Quantitative Research Methods 3 — Questions and Answers
Question 1: Which type of validity refers to the degree to which a test measures what it is theoretically supposed to measure?
- Criterion validity
- Content validity
- Construct validity (Correct answer)
- Face validity
Correct answer: Construct validity
Construct validity assesses whether an instrument actually measures the underlying theoretical construct it is designed to measure.
Question 2: A researcher uses every 10th person on a list as a sample. This is an example of:
- Simple random sampling
- Cluster sampling
- Purposive sampling
- Systematic sampling (Correct answer)
Correct answer: Systematic sampling
Systematic sampling selects every kth element from a list, providing an efficient alternative to simple random sampling.
Question 3: Cronbach's alpha is a measure of:
- Test-retest reliability
- Internal consistency reliability (Correct answer)
- Inter-rater reliability
- Parallel forms reliability
Correct answer: Internal consistency reliability
Cronbach's alpha quantifies the internal consistency of a scale by measuring how closely related a set of items are as a group.
Question 4: When a researcher incorrectly fails to reject a false null hypothesis, this is known as a:
- Type I error
- Sampling error
- Type II error (Correct answer)
- Systematic bias
Correct answer: Type II error
A Type II error (beta error) occurs when the null hypothesis is not rejected even though it is actually false.
Question 5: Which statistical technique is used to reduce a large number of correlated variables into a smaller set of uncorrelated components?
- Multiple regression
- Principal component analysis (Correct answer)
- Discriminant analysis
- Logistic regression
Correct answer: Principal component analysis
Principal component analysis (PCA) transforms correlated variables into orthogonal components that capture maximum variance.
Question 6: A scatter plot showing points closely clustered along a line sloping downward from left to right indicates:
- A strong positive correlation
- No correlation
- A strong negative correlation (Correct answer)
- A curvilinear relationship
Correct answer: A strong negative correlation
A downward-sloping tight cluster of points indicates that as one variable increases, the other decreases — a strong negative correlation.
Question 7: In hypothesis testing, statistical power is defined as the probability of:
- Committing a Type I error
- Correctly rejecting a false null hypothesis (Correct answer)
- Failing to reject a true null hypothesis
- Obtaining a sample that matches the population
Correct answer: Correctly rejecting a false null hypothesis
Power (1 − β) is the probability of correctly detecting a true effect by rejecting a false null hypothesis.
CRS Quantitative Research Methods 3
Which type of validity refers to the degree to which a test measures what it is theoretically supposed to measure?