I'm submitting this because it's an interesting attempt to teach a statistical method to a wide variety of people who may have not much maths education. The in

I'm submitting this because it's an interesting attempt to teach a statistical method to a wide variety of people who may have not much maths education. The interactive PDF is a useful guide to SPC charts (in the context of improvement work within the NHS), and there are free tools (always handy for NHS Trusts) to help people manipulate data.