" Race norming is the practice of converting individual test scores to percentile or standard scores within one’s racial group. In the process of race norming, an individual’s percentile score is not calculated in reference to all persons who took the test; instead, an individual’s percentile score is determined only in reference to others in the same racial group. After norming scores by percentile in separate racial groups, the lists are combined to make selection decisions. By norming within racial groups, the same raw score for Whites and Blacks can be converted to different percentile scores based on the distribution of scores for each racial group.

For example, suppose that a White candidate and a Black candidate each earn a raw score of 74 points on a test. If the White candidate’s test score is converted to a percentile only in reference to other White candidates and the Black candidate’s test score is converted to a percentile only in reference to other Black candidates, then the percentile scores earned by the two candidates may not be equal even though they attained the same raw test score. Perhaps the 74-point raw score for the White candidate may be at the 60th percentile of the White distribution of scores, whereas the 74-point score for the Black candidate may be at the 65th percentile of the Black distribution of scores. When the White and Black percentile scores are combined into a common list and selection decisions are made, the candidates who scored the same 74 raw points on the test might be treated very differently. For example, if the organization decides to hire only persons who scored at the 65th percentile and above, then the Black candidate would be selected and the White candidate would not. In another circumstance, the organization could decide to hire persons with the highest percentile first, which would mean that the Black candidate would be selected prior to the White candidate. "

― iresearchnet