ABSTRACT
A cumulative percentage helps to illuminate where a score falls in a distribution. A cumulative percentage is also known as a percentile rank. For instance, if 40" of a group had scores equal to or lower than an examinee's score, then that examinee has a percentile rank of 40. Percentile ranks are usually rounded to whole numbers when reported. Test makers often try out a test with a large group of examinees (known as the norm group) and then build a table such as the one in the excerpt below (known as a norms table). Those who subsequently take the test can convert their raw score (number of right answers) to a percentile rank using the table. In this way, the scores of later test takers are interpreted in relationship to how the norm group performed.
