How a broken projector improved my class

I teach in the "smart" classroom shown here. The students sit at computers and the professor has a podium computer. I use the overhead display during every minute of every class -- for presentations and live demonstrations of all sorts of things.

Yesterday morning, I walked into the classroom and discovered that the overhead display was broken, so we had to improvise. I sat down at one of the student computers in the middle of a row (the one with the arrow) and the students crammed in behind me -- sitting on chairs, tables and standing. All of my teaching material is online, so I was able to use the exact same PowerPoint decks and do the exact same demonstrations as I would have used from the podium if the projector had been working. The material was 100% the same -- only the seating arrangement changed. I don't know whether you can picture the scene, but it was cramped and disorderly. (I wish I had taken a picture).

Why am I telling you this? I have been teaching on and off during my entire career, and it was one of the best class sessions I can remember.

I taught a second section of the same class yesterday evening in the same room. The projector worked fine for about half an hour, then broke again. We crammed in behind the student computer and continued. The class lit up. Students listened, spoke, answered questions I threw out, asked a lot of good questions, made relevant comments and wisecracked and teased. It was even better than the morning class.

I was able to do this because my classes are small. A few students were too far from my screen to see it comfortably, so they turned on a couple of computers in the same row and navigated along with me. (We could have automated that by starting up a Google Hangout and sharing screens).

The success of our re-arranged room would not have surprised Michael Wesch, an award winning professor of anthropology who has long noted the impact of room design on teaching. (For a taste of his thoughts on the topic, watch this 3m 46s excerpt I cut from a talk he gave upon receiving an outstanding teaching award).

I'm no anthropologist, but these class sessions felt better than a small seminar around a conference table. The ad-hoc seating arrangement turned the classes into focused bull sessions by breaking down social barriers between the students and me and, more important, between themselves.

The success of this small, ad hoc arrangement is ironic, because it comes at a time when I have been writing about massive open online classes, MOOCS, and have proposed teaching one.

MOOCs have the potential to be extremely cost efficient, but my small class gathered around a PC was extremely costly -- the California taxpayers would not sustain it and the students would get tired of standing up after a while.

Could we capture some of the enthusiasm and interaction of the live class I had yesterday and share it with a mass audience taking a MOOC at the same time? Maybe.

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For more on Michael Wesch:

• A video excerpt from “A portal to media literacy” (3m 46s)
  
• A portal to media literacy (the entire talk 1:06:12)
  
• A vision of students today (4 m 45 s)
  
• About Michael Wesch
  
• A blog post on the characteristics of today’s students
  

Talking heads may or may not improve presentations, but they do add to conversations

MOOCs and other online classes give us an opportunity to learn what works in presentations. For example, I've proposed studies of the effect of playback speed or including a talking head in a presentation on comprehension, retention and engagement.

I'm not sure how these studies would turn out (though I have my suspicions), but I am sure that talking heads are important in coversation.

My certainty is based on a single anecdotal experience (of no scientific value). Some friends and I meet for a weekly podcast bull-session on technology (Yet another tech show). We do the podcast using a Google Hangout.

As you see here, video thumbnails of all the participants are shown under a larger head-shot of the person who is speaking. (Switching is automatic). But, check the thumbnails and you see that the second from the left is blank. That is because one of us had a slow Internet connection that night and could not stream video. We could hear what he said, but not see his face.

If you had asked me before we did that podcast whether not seeing him while he spoke would matter, I would have said "no" -- figuring that the audio conveyed all the information in a technical discussion.

If you ask me now, my answer is "yes, for sure." It had nothing to do with information or content. We understood what our invisible colleague was saying and he participated fully, but it felt weird.

Talking to disembodied people on the phone feels natural because there is no point of reference. But, in a mixed conversation, where you can see some, but not all of the participants, the difference is palpable. I don't know if it is because of subtle clues as to who gets the floor next, some primitive fear or something else, but it feels more natural to talk with someone you can see.

Two researchable questions: do talking heads and moving hands improve learning?

I would like to see studies testing the hypotheses that seeing a talking head or a hand writing on the screen improves student comprehension and retention.

I've developed a collection of modules for my digital literacy course. Each module contains an annotated PowerPoint presentation and other material. As I find time, I record videos of the PowerPoint presentations, using the annotation as a script.

To conserve bandwidth and storage space, I only use still images of the PowerPoint slides in my videos. There is no video of me speaking. I reasoned that my students knew what I looked like, and viewers who were not in my class could see what I looked like in a photo.

But, I notice that Google (left), Coursera (right) and others include video of the speaker's face during their presentations.

Is there evidence that talking heads improve comprehension and retention?

We see a similar contrast in the screencast videos produced by Udacity (left) and the Khan Academy (right}. Udacity videos are screencasts with superimposed video showing the teacher's hand and pen while drawing and writing on the screen (with noticeable parallax). Khan produces screencasts in which only a cursor is shown.

Does seeing the hand and pen improve comprehension and retention?

(If these research questions sound interesting, see a proposal for a related study of the effect on comprehension and retention of varying playback speed and bullet point images).

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.