Percentile rank identifies the percentage of a student’s peer group (e.g., grade level) that a student’s score surpassed. Percentile rank is useful in comparing an individual student's performance with those of other students within a defined group. For example, a student receives a test score of 66 and a percentile rank of 83. This means that a score of 66 is higher than 83% of the comparison group. The comparison group may be local, in which the group represents students within a school or a district; or national, in which the group represents students across the nation. The performance of these groups can differ and, therefore, interpretation can be confusing. As in the example above, a score of 66 can have a national percentile of 83 and a district percentile of 54. While the student is in the middle of the group at the local level, nationally the student performed well, as did the other students in the district.