ASPPB Research Methods & Psychological Foundations 2 — Questions and Answers
Question 1: A researcher finds a Pearson r = 0.65 between depression scores and sleep quality. Which conclusion is most appropriate?
- Depression directly causes poor sleep
- Poor sleep directly causes depression
- There is a moderate positive relationship between the two variables (Correct answer)
- The variables share 65% of their variance
Correct answer: There is a moderate positive relationship between the two variables
A correlation coefficient of 0.65 indicates a moderate positive relationship but does not imply causation.
Question 2: Which experimental design best controls for history effects in longitudinal research?
- Pre-test/post-test design without a control group
- Solomon four-group design (Correct answer)
- Cross-sectional design
- Case study design
Correct answer: Solomon four-group design
The Solomon four-group design controls for both testing effects and history effects by including groups with and without pretests.
Question 3: A psychologist uses snowball sampling to recruit participants with a rare phobia. The primary limitation of this approach is:
- Small sample size
- Non-random selection leading to limited generalizability (Correct answer)
- Inability to measure the target construct
- High cost relative to random sampling
Correct answer: Non-random selection leading to limited generalizability
Snowball sampling relies on participant referrals, producing a non-random sample that may not generalize to the broader population.
Question 4: In signal detection theory, a 'miss' refers to:
- Reporting a signal when none is present
- Correctly reporting no signal
- Failing to detect a signal that is actually present (Correct answer)
- Correctly detecting a present signal
Correct answer: Failing to detect a signal that is actually present
A miss (false negative) occurs when a signal is present but the observer fails to detect it.
Question 5: Which statistical test is most appropriate when comparing means across three or more independent groups?
- Independent samples t-test
- Pearson correlation
- One-way ANOVA (Correct answer)
- Chi-square goodness of fit
Correct answer: One-way ANOVA
One-way ANOVA is designed to compare means across three or more independent groups while controlling the Type I error rate.
Question 6: Construct validity is best evaluated by examining:
- Whether the test covers all aspects of the domain it measures
- The correlation between a new measure and an established gold-standard measure
- The pattern of correlations with theoretically related and unrelated variables (Correct answer)
- The consistency of scores across repeated administrations
Correct answer: The pattern of correlations with theoretically related and unrelated variables
Construct validity is supported through convergent and discriminant evidence—correlating with related measures and not correlating with unrelated ones.
Question 7: A within-subjects (repeated measures) design increases statistical power primarily by:
- Increasing the number of independent variables
- Removing individual difference variance from the error term (Correct answer)
- Using a larger alpha level
- Eliminating demand characteristics
Correct answer: Removing individual difference variance from the error term
Repeated measures designs use each participant as their own control, removing between-subject variability from the error term and increasing power.
ASPPB Research Methods & Psychological Foundations 2
A researcher finds a Pearson r = 0.65 between depression scores and sleep quality.
Which conclusion is most appropriate?