09. Independent Samples T-Test vs. Mann-Whitney U Test: Strengths & Weaknesses

Often, biomedical scientists analyze right-skewed outcomes with small to moderate sample sizes using nonparametric methods. Alternative approaches, such as transformations, reduce interpretability of outcomes but may boost power in certain settings. This study compares the strengths and weaknesses of using two-sample t-tests and Mann-Whitney U tests, specifically for outcomes with right-skewed distributions. First, simulations are used to compare the power of each of these tests while also examining each test's interpretability and appropriateness in real world data. Second, real data examples will be given to demonstrate the differences in results and interpretability between methods.

Mann-Whitney U test

independent samples t-test

biostatistics

interpretability

power 

Beginner

Knowledge

Women in Statistics and Data Science 2025