The percentile rank of a score is the percentage of scores in its frequency istribution which are lower. For example, a test score which is greater than 85% of the scores of people taking the test is said to be at the 85th percentile. Percentile ranks are commonly used to clarify the interpretation of scores on standardized tests. For the test theory, the percentile rank of a raw score is interpreted as the percentages of examinees in the norm group who scored below the score of interest (Crocker & Algina, 1986).