Point-biserial correlation coefficient

The punktbiseriale Correlation is a measure of association that can be used when the relationship between an interval- scaled feature and a dichotomous characteristic is to be calculated.

For simplicity, it is assumed that the dichotomous feature of the values ​​0 and 1 can take. The carriers of the trait are divided according to their value in two groups. Then the punktbiseriale correlation coefficient is defined by

Or where the mean values ​​of the feature in the groups with and represent and and represents the quotient of the dichotomous trait: .