The retrograde motion of planets and children: Interpreting percentile rank

A common method used to interpret raw scores is to convert them into percentile rank. The broad application of percentile rank in almost all norm-referenced tests, and the exclusive use in some tests, requires the conversion of raw scores. Because percentile rank is not a linear transformation of raw scores, percentile-rank transformation in the lower and upper part of the raw-score distribution relates percentile rank and raw scores differently than in the center of the raw-score distribution. This paper describes the popularity of using percentile rank and offers an interpretation of the use of percentile rank with normal and skewed score distributions.