Over recent years there has been a major reform movement in the USA focussed on the teaching of calculus in colleges. Part of this development is an approach to teaching mathematical ideas termed the Rule of Four. The approach is totally in tune with the UK approaches to teaching statistics developed over recent years. Discussions at the RSS Centre for Statistical Education have led to a statistically oriented version of this Rule. The purpose of this article is to define and illustrate this Statistical Rule of Four. Any statistics teacher reading this will be well familiar with the four elements of this Rule. So in a sense this article is redundant. However the issue raised here is not do we know the ideas but do we put them together in practice? This short article is thus a reminder. The box below gives the basic statement of the Rule:
