A term used for reporting test results that has some of the same characteristics as percentile ranks, but can be averaged to make more meaningful comparisons across test results for different content areas and grade levels.

A normalized standard score with a mean of 50 and a standard deviation of 20.06; has the same range and midpoint as percentile rank scores but is an equal interval scale.

An achievement test norm-referenced sore that describes the performance of a student relative to other students (the norming population). This score is derived from percentile ranks, but in contrast to percentiles (an ordinal scale), NCE provides an equal-interval scale. Students with a zero NCE have maintained their pretest achievement status at posttest. A mean NCE gain significantly different from zero revels that a significant change in achievement status in the student population has occurred from pretest to posttest.