Proportional Circle Map

(Graduated Circle Map image bottom middle)

http://personal.frostburg.edu/sbriggs0/maps.htm

Proportional circle maps scale the size of circles proportionally to the data value found at that particular location. They simply show that the larger the symbol equals more of the statistical value at a certain location. Proportional circle maps can easily conveys information when the circles are classed and that a key exists somewhere on the map. A proportional circle map without a class key can be confusing and misrepresent the data when the circles have common shapes. The proportional circle map shown above is of Walmart store locations in the United States which has a class key. Information is effectively expressed because the circles vary in size and are shown in an effective range that can be used on the United States size map.