Proportional Circle Map

 

Proportional circle maps are pretty much what the title says it is. These maps use circles to represent the information and each circle can vary in size. Usually the size of the circle is based on population but you can pretty much use whatever you want. Usually the bigger the population the bigger the circle. This map here shows the American Indian population of the Midwestern states from the census bureau of 1990. You can see each population represented by circles and the states with bigger population had big circles and small population states had small circles. The legend provided gives you the estimated numbers of each circle.

 

 

http://www.neiu.edu/~nerobert/Cartography.htm