Multimedia Learning by Richard E. Mayer

A few years ago, I was skeptical of PowerPoint, going along with the assumption that PowerPoint presentations had to be dull. I unthinkingly bought presentation guru Edward Tufte's claim that PowerPoint is evil, that "Power corrupts and PowerPoint corrupts absolutely."

Well, I'm a convert -- PowerPoint presentations are at the heart of my electronic text. I believe presentations combining slides and narration can be effective teaching tools, and I just read a book of research supporting that claim.

Richard E. Mayer, a UCSB psychologist, reports on 93 controlled studies in his book Multimedia Learning. Mayer's experiments test a dozen presentation principles, which he hypothesizes to be true, and 92 of those studies confirm the hypothesis.

For example, consider his redundancy principle, which holds that people learn better from graphics and narration than from graphics, narration and text -- the text is a redundant distraction.

To test this principle, Mayer and his colleagues ran five experiments in which one group learned from a multimedia presentation with narrated graphics and a second group saw the same presentation with text captions below the graphics. The non-caption group learned more in all five experiments.

He also gives theoretical explanations for his principles. The redundancy principle follows from visual overload in seeing captions and images simultaneously and mental effort expended in comparing spoken narration and written text. Mayer also explores the boundary conditions of his principles. Redundancy is less of a distraction if the captions are short or the text is shown after the narration finishes, not while it is playing.

Here are Mayer's twelve principles. Don't be bound by them, but use them as a checklist when going back over an old presentation or planning a new one.

• Coherence Principle: People learn better when extraneous words, pictures, and sounds are excluded rather than included.
  
• Signaling Principle: People learn better when cues that highlight the organization of the essential material are added.
  
• Redundancy Principle: People learn better from graphics and narration than from graphics, narration, and on-screen text.
  
• Spatial Contiguity Principle: People learn better when corresponding words and pictures are presented near rather than far from each other on the page or screen.
  
• Temporal Contiguity Principle: People learn better when corresponding words and pictures are presented simultaneously rather than successively.
  
• Segmenting Principle: People learn better when a multimedia lesson is presented in user-paced segments rather than as a continuous unit.
  
• Pre-training Principle: People learn better from a multimedia lesson when they know the names and characteristics of the main concepts.
  
• Modality Principle: People learn better from graphics and narration than from animation and on-screen text.
  
• Multimedia Principle: People learn better from words and pictures than from words alone.
  
• Personalization Principle: People learn better from multimedia lessons when words are in conversational style rather than formal style.
  
• Voice Principle: People learn better when the narration in multimedia lessons is spoken in a friendly human voice rather than a machine voice.
  
• Image Principle: People do not necessarily learn better from a multimedia lesson when the speaker’s image is added to the screen.

Let me close by suggesting two Mayer-like experiments that I would like to see run. One is a test of the effectiveness of showing images followed by the images with captions, the other a study of the effect of changing the tempo of a presentation. I'd love to hear the results if you run the experiments.