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 question asks to identify which of the listed statistical tests are parametric. Parametric tests are those that make certain assumptions about the population from which the sample is drawn, most commonly the assumption that the data are normally distributed. Nonparametric tests do not require such assumptions and are often used with ordinal data or when the normality assumption is violated.
Step 2: Detailed Explanation:

A. Spearman rank order correlation: This is a nonparametric test that measures the strength and direction of association between two ranked variables. It is the nonparametric equivalent of the Pearson correlation.
B. Pearson product moment correlation: This is a parametric test that measures the linear relationship between two continuous variables. It assumes that the data are normally distributed.
C. t-test: This is a parametric test used to compare the means of two groups. It assumes that the data in both groups are normally distributed and have equal variances.
D. Mann-Whitney U test: This is a nonparametric test used to compare the medians of two independent groups. It is the nonparametric equivalent of the independent samples t-test.
Based on this analysis, only the Pearson correlation and the t-test are parametric statistics.
Step 3: Final Answer:
The correct combination of parametric statistics is B and C only.