Multimedia learning occurs when a learner builds a mental representation from words and pictures that have been presented. For purposes of research program, multimedia instructional messages are presentations of material using words and pictures that are intended to foster learning. The pictures can be static graphics such as photos, drawings, maps, charts, figures, and tables or dynamic graphics such as video or animation. Multimedia learning occurs if one constructs a mental representation of the lightning system based on the words and pictures in the multimedia instructional message. In this case, one must build a cause-and-effect model of how a change in one part of the system causes a principle-based change in another part, and so on. For example, when cool air comes over a warm surface, the cool air becomes heated and rises.