Venn or Euler Diagrams are structured representations of relationships, and commonly used in logic (Layman, 2005). In a Venn/Euler Diagram, each area (e.g. circles in the diagram below) represents a set of elements that share a common attribute. Overlapping areas indicate elements that share attributes of two or more areas. For example, sound scientific conclusions can be represented as a Venn/Euler Diagram: