I googled the term and found the Wikipedia entry below:
"For example, let us say we are conducting a study on success in college. If we find out there is a high correlation between student grades in high-school math classes and their success in college (which can be measured by many possible variables), we would say there is high criterion-related validity between the intermediate variable (grades in high-school math classes) and the ultimate variable (success in college). "
It seems that you need to find the correlation coefficient. Hope it helps.