[1][2] Affinity diagrams are a special kind of brainstorming tool that organize large amount of disorganized data and information into groupings based on natural relationships.
The process of creating an interrelationship diagram helps a group analyze the natural links between different aspects of a complex situation.
It uses a combination of tree and matrix diagramming techniques to do a pair-wise evaluation of items and to narrow down options to the most desired or most effective.
The matrix diagram enables you to analyze relatively complex situations by exposing interactions and dependencies between things.
Different shaped boxes are used to highlight risks and identify possible countermeasures (often shown as "clouds" to indicate their uncertain nature).