ABSTRACT
In designing an instructional diagram, it is important to know as much as possible about what the students might ‘do’ with that diagram when they come across it in an instructional resource. We can think of a diagram as a tool for learning. It is a tool that students can use in their minds to carry out the thinking processes required to perform particular learning tasks. Like any tool, a diagram's effectiveness depends on how well it is used by its ‘operator’ (the person viewing the diagram). Even the best-designed instructional diagram imaginable can only be effective if students use it properly.
