During the last decade, cognitive researchers identified three major challenges facing the use of multimedia materials in instruction. The first challenge is the inclusion of extraneous content that competes with the essential information for limited cognitive resources. Researchers found that including extraneous material in multimedia materials may cause learners to engage in extraneous processing-by using their processing capacity to attend to and process material that is not essential to building a mental model of the to-be learned content. The second challenge facing the use multimedia learning materials is when the lesson contains some interesting but extraneous details, and it is not possible to delete the extraneous material. The third challenge facing multimedia learning content occurs when the learning content is dynamic and too complex and the designer can't delete the material because it is needed for the learner to build a coherent mental representation. To overcome these challenges, multimedia designers should follow three key elements in the learning materials: (1) help learners to reduce extraneous processing-cognitive processing that does not support the instructional goal and is attributable to confusing instructional design; (2) help learners to manage essential processing- cognitive processing needed to mentally represent the incoming material and that is attributable to the complexity of the material; and (3) help learners to foster generative processing- cognitive processing aimed at making sense of the incoming material, including organizing it and integrating it with prior knowledge (R. Mayer, 2005; Sweller, 1999).