# Definition

In statistics, Spearman's rank correlation coefficient or Spearman's rho, named after Charles Spearman and often denoted by the Greek letter ρ (rho) or as rs, is **a nonparametric measure of statistical dependence between two variables**.

The Spearman's rank correlation is used when the variables are not continuous (measure on an ordinal scale) and the relationship between the two variables supposed monotonic (but not necessary linear).

# In practice

Spearman's rank correlation is used **when the Pearson's correlation cannot be performed**, i.e. when the variables don't follow a normal distribution, have no linear relationship and are measured on a non interval scale as an ordinal scale.

# How to use it on EasyMedStat ?

- Go to Statistics > Test variables
- Select two Numeric variables you would like to analyze and click on "Which tests can I do ?"
- Click on "Find a correlation between ... and ...

If conditions are met, the Pearson correlation will automatically be used instead of Spearman's correlation.