# non-parametric

## Significance Test for Kendall's Tau-b

A variation of the standard definition of Kendall correlation coefficient is necessary in order to deal with data samples with tied ranks. It known as the Kendall’s tau-b coefficient and is more effective in determining whether two non-parametric data samples with ties are correlated.

## Kendall Rank Coefficient

The correlation coefficient is a measurement of correlation between two random variables. While its computation is straightforward, it is not readily applicable to non-parametric statistics.

## Kruskal-Wallis Test

A tutorial of performing statistical analysis with the Kruskal-Wallis test.

## Mann-Whitney-Wilcoxon Test

A tutorial of performing statistical analysis with the Mann-Whitney-Wilcoxon test.

## Wilcoxon Signed-Rank Test

A tutorial of performing statistical analysis with the Wilcoxon signed-rank test.

## Sign Test

A tutorial of performing statistical analysis with the sign test.

## Non-parametric Methods

A statistical method is called non-parametric if it makes no assumption on the population distribution or sample size.

This is in contrast with most parametric methods in elementary statistics that assume the data is quantitative, the population has a normal distribution and the sample size is sufficiently large.