Diagram Understanding

Abstract

When two scientists talk to each other about their ideas, they typically do not restrict themselves to words; they also draw diagrams, label them, and tell each other what these diagrams represent. “Here’s a ball rolling down an inclined plane,” one scientist may say, for example, and simultaneously sketch a diagram such as that in Figure 1. In order to understand this kind of conversation, the scientists must recognize the circle as such and associate it with a ball, recognize the arrow and associate it with a vector, and recognize the triangle and associate it with a ramp. After these associations are made, the behavior of the objects in the diagram is then determined. The diagram is a kind of notation with which to solve simple physics problems. Alternatively, the scientists may use a standardized notation whose meaning is known by everyone in the culture, such as algebra. In either case, there is a specific association between visual objects and descriptions for these objects.