Some people believe – incorrectly – that all data collected and used for analysis must be normally distributed. But there are tools that do not need normality, as well as a number of ways to acheive normality if tools requiring it are necessary.
Data transformation, particularly the Box-Cox power transformation, is a remedial action that may help to make data normal. By understanding transformation and the Box-Cox method, practitioners will be better prepared to work with non-normal data.
Practitioners can benefit from an overview of normal and non-normal distributions, as well as familiarizing themselves with some simple tools to detect non-normality and techniques to accurately determine whether a process is in control and capable.
