Definition: Percentile scores are commonly reported on most standardized assessments a child takes in school. Percentile literally means per hundred. Percentile scores on teacher-made tests and homework assignments are developed by dividing the student's raw score on her work by the total number of points possible. The resulting number is converted from a decimal number by moving the decimal point two places to the right of the number.
On a commercially produced, norm-referenced or standardized test, percentiles are calculated in much the same way, although the calculations are typically included in examiners manuals or calculated with scoring software and are not individually calculated by examiners or teachers.
If a student scores at the 75th percentile on a norm-referenced test, it can be said that she has scored at least as well, or better than, 75 percent of students her age from the normative sample of the test. Several other types of standard scores may also appear on assessment reports.
Alternate Spellings: %ile, percentile scores, ranking, percentage scores
Examples: On many nationally norm-referenced intelligence tests, a standard score of 100 corresponds to the 50th percentile. Students scoring scoring at this level are well within the average range.
