Pearson's contingency coefficient
The measure of the relationship between the two qualitative (non-measurable) features X and Y when the data is presented in the form of a contingency table. This coefficient takes values from the interval [0; 1]. Its value of 0 means that the features are independent (uncorrelated). A value of 1 indicates a functional relationship. The factor does not indicate the direction of dependence. The value of the C-Pearson contingency coefficient depends on the size of the independence table (the coefficients from the various arrays should be normalized in order to compare them).