A double bubble map is a type of thinking map. According to Thinking Maps, double bubble maps are a tool to compare and contrast two different items or points.
A double bubble map is much like a Venn Diagram. The two center circles hold the items being compared. The outside bubbles hold items, descriptive phrases and other factors that describe only the object to which they are connected. The bubbles on the inside that connect to both center circles contain information that pertains to both the items in the center circles. As a result, the double bubble map shows areas in which the two items differ and others in which they share similar traits.