Which test is the parametric counterpart to the Wilcoxon test for two related samples?

Which test is the parametric counterpart to the Wilcoxon test for two related samples?

• A. Paired samples t-test
• B. Unpaired t-test
• C. One-way ANOVA
• D. Mann-Whitney U

Answer: (A)

When you have paired observations and want to compare their mean difference using a parametric approach, you use the paired samples t-test. It assesses whether the average difference between the matched pairs is zero, relying on the differences being roughly normally distributed. This mirrors the Wilcoxon signed-rank test, which is its nonparametric counterpart when normality can't be assumed. The other options don't fit: an unpaired t-test is for independent groups, not paired; one-way ANOVA compares means across more than two groups; Mann-Whitney U is the nonparametric alternative for independent samples, not for related pairs.

When you have paired observations and want to compare their mean difference using a parametric approach, you use the paired samples t-test. It assesses whether the average difference between the matched pairs is zero, relying on the differences being roughly normally distributed. This mirrors the Wilcoxon signed-rank test, which is its nonparametric counterpart when normality can't be assumed. The other options don't fit: an unpaired t-test is for independent groups, not paired; one-way ANOVA compares means across more than two groups; Mann-Whitney U is the nonparametric alternative for independent samples, not for related pairs.