Extraneous overload occurs when essential cognitive processing (required to understand the essential material in a multimedia message) and extraneous cognitive processing (required to process extraneous material or to overcome confusing layout in a multimedia message) exceed the learner's cognitive capacity. According to the cognitive theory of multimedia learning, the five ways to handle an extraneous overload situation are to: eliminate extraneous material (coherence principle), insert signals emphasizing the essential material (signaling principle), eliminate redundant printed text (redundancy principle), place printed text next to corresponding parts of graphics (spatial contiguity principle), and eliminate the need to hold essential material in working memory for long periods of time (temporal contiguity principle). The research reviewed in this chapter shows that instructional designers should be sensitive to the limitations of working memory by being careful about the amount and layout of information that is presented to learners.

This chapter examines the research evidence concerning four principles of multimedia design that are based on social cues: the personalization, voice, image, and embodiment principles. The personalization principle is that people learn more deeply when the words in a multimedia presentation are in conversational style rather than formal style. The voice principle is that people learn more deeply when the words in a multimedia message are spoken in a human voice rather than in a machine voice. The image principle is that people do not necessarily learn more deeply from a multimedia presentation when the speaker's image is on the screen rather than not on the screen. The embodiment principle is that people learn more deeply when on-screen agents display human like gesturing, movement, eye contact, and facial expressions. The research reviewed in the chapter shows that instructional designers should be sensitive to social considerations as well as cognitive considerations.