Fundamentals of Statistics contains material of various lectures and courses of H. Lohninger on statistics, data analysis and here for more.

Venn Diagram

Venn diagrams have been introduced around 1880 by John Venn and are a simple but effective method of visualizing the sample space and its individual events. Furthermore, Venn diagrams can be used to display logical operations on sets, such as unions, or intersections.

A Venn diagram consists of a frame which represents the population P, and one ore more arbitrarily formed, closed shapes which are contained in P representing partial sets to be displayed. The negation of the partial set A (complementary set A') is equal to the outer area of the set within the boundaries of P.

The Venn diagrams illustrate some axioms of Boolean algebra in quite a natural form, as any combination of sets can be formed by putting them on top of each other. The resulting regions can be interpreted as logical AND or logical OR.