Multimedia is widely used in human-human and human-machine communication. In the context of educational practice, multimedia is regarded as a powerful tool for presenting learning materials, as compared to the traditional text-oriented medium. The primary advantage of multimedia presentations (MPs) is that information can be presented in different codes (e.g., verbal and non-verbal) and modalities (e.g., in visual and auditory formats) at the same time. Besides, some multimedia learning environments also allow learners to interact with the media. Due to these advantages, it appears convincing that multimedia can deliver information more effectively and therefore motivate learners to engage themselves more deeply in the learning process. However, over the last decade, empirical studies on the effects of MPs on learning have yielded inconclusive results.
The objective of this thesis is to investigate the following issues: 1. How do different MPs influence the way in which people process information? 2. Under which conditions do the various kinds of MPs facilitate learning? 3. How do different modalities for presenting information interact with regard to the cognitive load on the side of the recipients?
It should be noted that the current thesis not only focuses on examining the effect of MPs on learning outcomes but also on investigating how different MPs affect information processing. An eye-tracking technique is therefore employed to observe subjects' eye movements during learning.
The thesis in hand mainly consists of two parts. The first part (from Chapter 2 to Chapter 6) refers to the theoretical background to my research topic, and the second part (Chapter 7 and Chapter 8) contains new empirical data on multimedia-based learning.
In Chapters 7 and 8, I report on two experiments that I conducted within the framework of this thesis. The results of the first experiment showed that moving pictures were not superior to static pictures in regard to learning efficiency. However, moving pictures appeared to be easier to understand and remember. Presenting texts auditorily had a positive effect on learning efficiency. Yet this effect was limited to the moving-picture conditions. That is, the modality effect was only partially confirmed in this experiment. The results of the second experiment indicated that both the split-attention effect and the modality effect require further modification. When static graphics were displayed together with texts, single-modality (only visual) presentation (SMP) was not less effective than dual-modality (auditory plus visual) presentation (DMP), a result which blatantly contrasts with the claims of the cognitive load theory. The widely-accepted view that DMP should be superior to SMP can no longer be upheld in light of the evidence.