ABSTRACT
How often have you heard instructors say that ‘a picture is worth a thousand words’? This statement reflects the common belief that visuals are somehow especially effective as a teaching resource. The diagram is a type of instructional visual that is widely used across many subjects, particularly those which involve technical subject matter. However, not all the diagrams found in teaching materials are equally successful in promoting the desired learning outcomes. This can be because the diagrams are so poorly designed that they actually hinder, rather than help, learning. However, even well-designed diagrams can be ineffective if the student is given insufficient support in how to use them. So, perhaps the adage about pictures could be rewritten as ‘a diagram can be worth a thousand words, provided it has been well designed and is sufficiently supported’. As with any instructional resource, the main reason for using diagrams in teaching materials is to help students learn more efficiently and effectively. In many situations this means that instructional diagrams aim to teach students how to:
perform new tasks in an acceptable way, or
improve the way they perform their existing tasks.
