Extraneous processing occurs when suboptimal instructional design causes learners to engage in cognitive processing irrelevant to the instructional goal. This chapter explores five principles for reducing extraneous processing in multimedia learning: coherence, signaling, redundancy, spatial contiguity, and temporal contiguity. The coherence principle is that people learn better when extraneous information is excluded from multimedia lessons. The signaling principle is that people learn better when cues are added to highlight the organization of the essential information. The redundancy principle is that people learn better when multimedia lessons include graphics and spoken text rather than graphics, spoken text, and printed text. The spatial contiguity principle is that people learn better when words and corresponding graphics are physically integrated rather than separated. The temporal contiguity principle is that people learn better when words and corresponding graphics are presented simultaneously rather than sequentially.

A pedagogical agent (PA) is a computerized humanlike onscreen image whose purpose is to guide the learner’s attention and facilitate learning. In this chapter, the main findings from research on pedagogical agents are reviewed and a meta-analysis is used to reveal the specific role of PAs on learning outcomes, yielding an effect size of g = .45 on transfer performance and g = .23 on retention performance. We also examine explanations for why PAs could have a positive effect on learning performance based on social agency theory, the embodiment principle, and the signaling principle. In addition, this chapter summarizes the main moderating variables for the effect of PAs, including characteristics of the learner such as the learner's prior knowledge, characteristics of the learning environment such as the subject matter, and characteristics of the PA such as voice and gesture.

The signaling principle, also known as cueing principle, refers to the finding that people learn more deeply from a multimedia message when cues are added that guide attention to the relevant elements of the material or highlight the organization of the essential material. In this chapter, the main findings from research on signaling or cueing in multimedia learning are reviewed, addressing the effects of incorporating cues in the text, the picture, or both. In addition, the design of cues based on successful students’ eye movements and the effects of using experts’ or students’ eye movements as cues are discussed. This chapter shows that various types of cueing can have beneficial effects on learning and discusses potential boundary conditions.