This lesson gives a brief overview of what a stanine is and how it relates to a normal distribution. It also explains why stanines were important to storing testing information.
What Is a Stanine?
Stanine stands for standard nine and indicates nine statistical units from a scale of 1 to 9.
These units are used to indicate a performance level on a psychological or educational test. A stanine is easy to find because there are only nine units. Although stanines provide the same information as other standard scores, they are less accurate. For example, in the table below, only stanines 4, 5, and 6 are within an average range of classification.
However, within the Standard Score table below the Stanine table, there is a range of scores from 90 to 109.
Stanines in Math
In math, a stanine is a way to scale test scores. The mean (average) is always 5 with a standard deviation of two.
A standard deviation is a measure of dispersion or variation in the distribution of a data set. Stanines are integers and can be used to convert a test score into a single digit. This was important when computers were the size of dinosaurs but used small paper punch cards because these were the most popular method of storing testing information. Today there are very few tests that use stanines to report testing information. However, these scores can be useful in understanding a relative range of a performance.
The low end of the stanine are the numbers 1, 2, and 3 (below average). The higher ranging numbers are 7, 8, and 9 (above average). Of course, in the middle are 4, 5, and 6 (average). Students who score in the middle are passing but not achieving above average grades. Using the stanine scores, you can see where a student is doing well or where extra help may be needed. For example, if Mary achieved a stanine score of 7 in math and a stanine score of 4 in English, this would indicate she excels in math but may need tutoring in English.
To summarize, a stanine, or standard nine, consists of nine statistical units on a scale of 1 to 9. These units can show a student’s performance on a psychological or educational exam. They often need to be combined with other data, however, to be completely effective.