Somers' D, normally used to measure concordance in a contingency table, is reported on the output of commonly used statistical packages. Consequently, researchers who wish to use the MCR can obtain this statistic without any special programming or time-consuming hand calculations. However, some caution must be used in obtaining the MCR from a statistical package, because Somers' D has two forms. In one form, the rows are the independent variable; in the other, the columns are the independent variable. The MCR is the form of Somers' D that is opposite to what might be expected. (Author abstract modified)