Abstract: In the 1990’s there were many arguments over the usefulness of media in computer-based education. Today it is accepted that whilst Pedagogy and the quality of the teaching are of prime importance in the education process, media are also important because they affect the cognitive efficiency of the learning process. There have been many poorly controlled experiments to detect the effect of media in education, and in other areas such as process control the effects of media have not been well understood. There is now a considerable body of evidence that can be used to influence the design of computer-based educational material backed by sound psychological principles about human capabilities and limitations. Theories such as Dual Coding Theory and Cognitive Load Theory can now be applied and reasonable predictions obtained. The tutorial will examine the theories and evidence that can support the design of appropriate multimedia interfaces particularly applied to computer-based education.