A standard score – also known as a z-Score – is a set of scores with the same mean and the same standard deviation. The standard score shows how far away from the mean any individual score is. By converting the “raw” test scores of your candidates into a standard score, it allows results to be compared more easily. 

Standard scores and standard deviations are different for different tests, but both help to determine which scores are above average, average, and below average when compared with other test-takers.