Diagrams are essential in most fields of human activity. There is substan tial interest in diagrams and their use in many academic disciplines for the potential benefits they may confer on a wide range of tasks. Are we now in a position to claim that we have a science of diagrams-that is, a science which takes the nature of diagrams and their use as the central phenom ena of interest? If we have a science of diagrams it is certainly constituted from multiple disciplines, including cognitive science, psychology, artificial intelligence, logic, mathematics, and others. If there is a science of diagrams, then like other sciences there is an appli cations, or engineering, discipline that exists alongside the science. Applica tions and engineering provide tests of the theories and principles discovered by the science and extend the scope of the phenomena to be studied by gen erating new uses of diagrams, new media for presenting diagrams, or novel classes of diagram. This applications and engineering side of the science of di agrams also comprises multiple disciplines, including education, architecture, computer science, mathematics, human-computer interaction, knowledge ac quisition, graphic design, engineering, history of science, statistics, medicine, biology, and others.
