Question

Which of the following are parametric statistics?
A. Spearman rank order correlation
B. Pearson product moment correlation
C. t-test
D. Mann-Whitney U test
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. A, B, C and D
• D. B and C only

Hint:

A simple way to remember the difference is to associate "parametric" with "parameters" of a population, like the mean and standard deviation, which are central to tests like the t-test and Pearson correlation. Nonparametric tests, like Spearman's and Mann-Whitney U, often work with ranks or medians instead of means.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The objective is to identify which of the provided statistical tests are parametric. Parametric tests necessitate assumptions about the population from which the sample originates, most notably that the data follows a normal distribution. Conversely, nonparametric tests do not impose such assumptions and are often employed with ordinal data or when the normality assumption is not met.

Step 2: Detailed Explanation:


A. Spearman rank order correlation: This is a nonparametric test assessing the strength and direction of association between two ranked variables. It serves as the nonparametric counterpart to the Pearson correlation.

B. Pearson product moment correlation: This is a parametric test evaluating the linear relationship between two continuous variables, predicated on the assumption of normally distributed data.

C. t-test: This is a parametric test used for comparing the means of two groups. It assumes that data within both groups are normally distributed and exhibit equal variances.

D. Mann-Whitney U test: This is a nonparametric test employed to compare the medians of two independent groups. It is the nonparametric equivalent of the independent samples t-test.

Consequently, only the Pearson correlation and the t-test are classified as parametric statistics.

Step 3: Final Answer:
The correct selection of parametric statistics is limited to B and C.