Which statement about the Wilcoxon Signed Rank test is true?

Which statement about the Wilcoxon Signed Rank test is true?

• A. Used for independent samples with nominal data
• B. Used for correlated samples with interval data
• C. Used for comparing means with large samples
• D. Used for related samples with ordinal data

Answer: (D)

Wilcoxon Signed Rank test is a nonparametric method designed for related (paired) samples when you want to know if there’s a systematic difference between two related measurements. It doesn’t assume normal distribution and works with data that can be ordered, such as ordinal data, or continuous data that aren’t normally distributed. The test looks at the differences within each pair, ranks the absolute differences, and then examines the signs of those differences to see if they tend to favor one side of zero. This approach focuses on differences in paired measurements rather than means, which is why it’s appropriate for ordinal data and non-normal distributions. So, the statement that it’s used for related samples with ordinal data is true. It isn’t for independent samples, it isn’t framed around comparing means, and nominal data aren’t suitable because they can’t be ranked.

Wilcoxon Signed Rank test is a nonparametric method designed for related (paired) samples when you want to know if there’s a systematic difference between two related measurements. It doesn’t assume normal distribution and works with data that can be ordered, such as ordinal data, or continuous data that aren’t normally distributed. The test looks at the differences within each pair, ranks the absolute differences, and then examines the signs of those differences to see if they tend to favor one side of zero. This approach focuses on differences in paired measurements rather than means, which is why it’s appropriate for ordinal data and non-normal distributions.

So, the statement that it’s used for related samples with ordinal data is true. It isn’t for independent samples, it isn’t framed around comparing means, and nominal data aren’t suitable because they can’t be ranked.