Stanines

Stanines are a type of norm-referenced score transformation. The term stanine is an abbreviation for standard nines. Stanines range from 1 (the lowest 4% of the distribution) to 9 (the highest 4% of the distribution), and each stanine represents a score interval rather than a score point in the normal distribution. The stanine distribution is centered on the stanine of 5, which includes the range of percentile ranks between the 40 and 59. To interpret stanine scores, one needs to know the percentage of scores included in the interval for each stanine reported. Because stanine scores are normalized standard scores, it is possible to compare scores from diverse sets of data. For example, a student who earns a stanine of 8 on an ability measure and a composite stanine score of 5 on an achievement measure could be said to be achieving at a level well below his or her ability.