Concept Maps are a way to graphically represent ideas and how they relate to each other.
Concept maps may be simple designs illustrating a central theme and a few associated topics or complex structures that delineate hierarchical or multiple relationships.
J.D. Novak developed concept maps in the 1970's to help facilitate the research process for his students. Novak found that visually representing thoughts helped students freely associate ideas without being blocked or intimidated by recording them in a traditional written format.
Concept mapping involves defining a topic; adding related topics; and linking related ideas
Use Bubbl.us or search for more free mind-mapping tools on the web.