Test

Purpose

Biomedical Example

Wilcoxon Signed-Rank Test

Compare median differences in paired data

Testing whether blood sugar levels before and after treatment differ significantly

Mann-Whitney U Test

Compare medians between two independent groups

Comparing blood pressure between males and females.

Kruskal-Wallis Test

Compare medians across more than two independent groups

Comparing recovery times among three drug treatments.

Friedman Test

Compare medians in repeated measures from the same group

Effect of diet on cholesterol levels over time.

Chi-Square Test

Test independence or goodness-of-fit in categorical data

Association between smoking and lung cancer.

Spearman's Rank Correlation

Measure correlation between two ordinal or non-normally distributed variables

Association between stress level and heart rate.

Kolmogorov-Smirnov Test

Test if a sample differs from a reference distribution

Comparing sample distribution to a normal distribution.

Sign Test

Test for median differences in paired data

Effectiveness of a new drug on paired patient outcomes.