Assessment Terms Criterion Referenced Test (CRT) Criterion referenced tests assess an individual's performance on a specific set of standards or criteria. These criteria are based on specific skills or objectives the individual has been taught. The CRT measures the level to which the criteria have been met. Norm Referenced Test (NRT) Norm referenced tests compare an individual's performance on a test to other people who took the test. The results are reported in comparison to other people rather than how much of a specific criteria has been met. National Percentiles National Percentile ranks indicate relative standing of a student in comparison with other students in the same grade in the norm group who took that test at a comparable time of year. Percentile ranks range from a low of 1 to a high of 99, with 50 denoting average performance for the grade. The percentile rank is a way of comparing the relative ranking of a student who took the test at that grade level. A percentile of 74 indicates that the students did better than 73 of every 100 students who took the test. Stanines Stanine scores indicate a students relative standing in the national norm group. They range from a low of 1 to a high of 9. Stanine Scores of 1, 2, or 3 indicate functioning below average. Stanines of 4, 5, and 6 are considered average, and stanines of 7, 8 or 9 are considered above average. Normal Curve Equivalents (NCE) NCE's were developed to avoid problems that often occur with other types of scores. School personnel frequently try to aggregate percentile scores, but percentile scores should never be added, subtracted or averaged because the distance between points is not equal. At the upper and lower ends of the scale, the percentile points are farther apart than in the middle. Because of its equal-interval nature, any difference, such as 5 NCE's, has the same meaning, regardless of the part of the normal curve being referenced.