ABSTRACT
Law Encoding Diagrams, LEDs, are knowledge representations that correctly encode systems of one or more laws using the geometric and/or the topological structure of diagrams. In an instructional role, LEDs aim to focus learning on the formal relations defined by the correct laws, whilst using diagrammatic representations to aid comprehension. LEDs can be viewed as intermediate representations that aim to bridge the conceptual gulf between abstract laws and the behaviour of phenomena. It is anticipated LEDs will be adopted as key models in the foundation of expertise. This paper describes an investigation in which LEDs for momentum and energy conservation were used for instruction. The LEDs were implemented in a computer based discovery learning environment and the subjects given only minimal instruction on their use in problem solving. However, half the subjects used the LEDs for successful post-test solutions of different classes of problem and exhibited strategies that were expert-like, in marked contrast to their novice-like pre-test performance.
