correlation coefficient Matthews correlation coefficient Philippe Rocca-Serra phi coefficient Matthews Correlation Coefficient (or MCC) is a correlation coefficient which is a measure of the quality of binary (two-class) classifications, introduced by biochemist Brian W. Matthews in 1975. adapted from wikipedia: https://en.wikipedia.org/wiki/Matthews_correlation_coefficient and from: https://doi.org/10.1016/0005-2795(75)90109-9 ratio-based measure of association ready for release