PS 320
Statistical Methods in Psychology
3.0 Credits
Midterm Exam Review (Qns & Ans)
2025
Multiple Choice Questions (10 Questions)
©2025
,1. Question:
In hypothesis testing within psychology, a Type I error represents:
- a. Failing to reject a false null hypothesis
- b. Rejecting a true null hypothesis
- c. The probability of correctly rejecting a false hypothesis
- d. A result that has no practical significance
ANS: b. Rejecting a true null hypothesis
Rationale:
A Type I error occurs when we erroneously reject a null hypothesis that
is actually true. This is often denoted by the significance level (α).
2. Question:
Which statistic is commonly used as a measure of effect size in
psychological research for comparing means between two groups?
- a. Pearson’s r
- b. Cohen’s d
- c. Eta squared (η²)
- d. Odds ratio
ANS: b. Cohen’s d
Rationale:
Cohen’s d is used to measure the standardized difference between two
means, providing an estimate of the effect size independent of sample
size.
3. Question:
When conducting multiple regression analysis, which assumption is
most critical to ensure unbiased estimates of the regression coefficients?
- a. Homoscedasticity
- b. Normality of residuals
- c. Multicollinearity absence
- d. Linearity of relationships
ANS: d. Linearity of relationships
Rationale:
While all listed assumptions are important, the assumption of linearity—
©2025
, that there is a linear relationship between each predictor and the dependent
variable—is fundamental for the proper estimation in linear regression.
4. Question:
In analysis of variance (ANOVA), the F-test is used to determine
whether:
- a. At least one group mean is significantly different from the others
- b. The variances among groups are homogeneous
- c. The sample size is sufficient
- d. The data follows a normal distribution
ANS: a. At least one group mean is significantly different from the
others
Rationale:
The F-test in ANOVA compares the variance between groups to the
variance within groups to test the null hypothesis that all group means are
equal.
5. Question:
Which procedure is used to test whether the differences observed in a
non-parametric analysis are statistically significant when the data do not
meet parametric assumptions?
- a. Kruskal-Wallis test
- b. Pearson correlation
- c. ANOVA
- d. T-test
ANS: a. Kruskal-Wallis test
Rationale:
For data that violate parametric assumptions, the Kruskal-Wallis test is a
non-parametric alternative to one-way ANOVA for comparing more than
two groups on an ordinal or continuous outcome.
6. Question:
Which multivariate technique is used primarily to identify the
underlying factors that explain the pattern of correlations among observed
variables in psychological scales?
- a. Cluster analysis
©2025
Statistical Methods in Psychology
3.0 Credits
Midterm Exam Review (Qns & Ans)
2025
Multiple Choice Questions (10 Questions)
©2025
,1. Question:
In hypothesis testing within psychology, a Type I error represents:
- a. Failing to reject a false null hypothesis
- b. Rejecting a true null hypothesis
- c. The probability of correctly rejecting a false hypothesis
- d. A result that has no practical significance
ANS: b. Rejecting a true null hypothesis
Rationale:
A Type I error occurs when we erroneously reject a null hypothesis that
is actually true. This is often denoted by the significance level (α).
2. Question:
Which statistic is commonly used as a measure of effect size in
psychological research for comparing means between two groups?
- a. Pearson’s r
- b. Cohen’s d
- c. Eta squared (η²)
- d. Odds ratio
ANS: b. Cohen’s d
Rationale:
Cohen’s d is used to measure the standardized difference between two
means, providing an estimate of the effect size independent of sample
size.
3. Question:
When conducting multiple regression analysis, which assumption is
most critical to ensure unbiased estimates of the regression coefficients?
- a. Homoscedasticity
- b. Normality of residuals
- c. Multicollinearity absence
- d. Linearity of relationships
ANS: d. Linearity of relationships
Rationale:
While all listed assumptions are important, the assumption of linearity—
©2025
, that there is a linear relationship between each predictor and the dependent
variable—is fundamental for the proper estimation in linear regression.
4. Question:
In analysis of variance (ANOVA), the F-test is used to determine
whether:
- a. At least one group mean is significantly different from the others
- b. The variances among groups are homogeneous
- c. The sample size is sufficient
- d. The data follows a normal distribution
ANS: a. At least one group mean is significantly different from the
others
Rationale:
The F-test in ANOVA compares the variance between groups to the
variance within groups to test the null hypothesis that all group means are
equal.
5. Question:
Which procedure is used to test whether the differences observed in a
non-parametric analysis are statistically significant when the data do not
meet parametric assumptions?
- a. Kruskal-Wallis test
- b. Pearson correlation
- c. ANOVA
- d. T-test
ANS: a. Kruskal-Wallis test
Rationale:
For data that violate parametric assumptions, the Kruskal-Wallis test is a
non-parametric alternative to one-way ANOVA for comparing more than
two groups on an ordinal or continuous outcome.
6. Question:
Which multivariate technique is used primarily to identify the
underlying factors that explain the pattern of correlations among observed
variables in psychological scales?
- a. Cluster analysis
©2025
