Students typically encounter many obstacles while learning statistics. In 44 years of teaching I have discovered some distinctions that help students overcome these obstacles. This article will remove some sources of confusion concerning the relationship between statistical process control (SPC) and other statistical techniques. The distinctions made here have not been widely taught, but I’ve found that they are essential to the proper use of both SPC and the traditional statistical techniques. These distinctions will allow you to use SPC to improve quality, increase productivity, and gain competitive advantage, while also using traditional statistical techniques appropriately.

 …