Stanine Scores

Stanine scores are area-normalized standard scores that are standardized to have a mean of approximately 5 and a standard deviation of approximately 2. They are simple to define but may discard some of the detail in the original data.

Many statistical procedures assume that the data are normally distributed. Sometimes, nonlinear algebraic transformations such as logistic or arcsin transformations will produce the desired result, but when the non-normality is due to sampling or to the features of the measuring instrument itself, an area-normalizing transformation may be required. The stanine transformation provides a quick and simple way to accomplish this goal.

As with other area normalizations, the stanine transformation assigns transformed scores to be equivalent to the raw scores rather than computing the new scores. To obtain stanine ...