Want your lecture to be more than a talker and an undifferentiated mass of bent-headed note-takers? Consider “didaction,” a mix of exposition and student action. Didaction is what public school teachers do as a survival mechanism — most of their charges simply can’t stay focused for 50 consecutive minutes of “chalk and talk.” Your undergraduates are products of those skilled teachers who integrate three or four separate activities into a single class. You can’t do as many activities in the roughly 2,400 semester minutes you’ll have with students — about 10 percent of a high school teacher’s contact minutes — but you can do plenty to involve students, even if you’re speaking before classes the size of a small rock concert. Among them:
1. Brainstorm shout-outs: An easy way to involve a large group is to pose an open-ended question appropriate for brainstorming and just ask students to yell out ideas. For instance, when I lecture on Baby Boomers entering college in the 1960s I just ask students: “What are some of the values from their 1950s childhood that Baby Boomers might come to question?” I quickly jot down responses on the blackboard. It takes about a minute and chances are that I’ve already woven most of these into the lecture. But when I hit one the students suggested I turn to the blackboard and point to it.
2. Say it in pictures: PowerPoint is much maligned because it’s so poorly used. (Is there anything more boring or insulting than having someone read a slide to an audience?) It can, however, be a powerful tool if you use it like a combo overhead projector/slide projector. Show images and ask students to comment on them. Your “lecture” will consist mainly of summarizing the correct assumptions students extract from images, data, etc. Still images work much better in the classroom than video. Students often let moving images wash over them rather than drinking them in. Still images slow them down. Anytime you have data or geographic references, project them or don’t bother to mention them at all.
A variant is to have students listen to somebody who isn’t you. I like to use music. Recommendation: If you use music, and if it’s the lyric you want students to consider, either pass them out or project them. If there’s something in the music itself, cue students about what it is you want them to hear and when it’s coming. Ask for immediate feedback.
3. Be a story teller and solicit input: A skilled lecturer can turn information-giving into a story. I once heard an astronomer tell the story of the lifecycle of stars with such finesse that he could stop and ask listeners what would happen next. Most of the time the answers were right, but when they weren’t he went back to storytelling to explain the error.
4. Do a demonstration of the concept just explained: This has been a staple of good chemistry profs for years, but it works for most disciplines. Give the facts, properties, or sequence then set up a quick experiment or scenario that asks students to apply what they’ve just heard. It need not be complex. I once projected and explained the phases of the Chinese concept of dynastic cycles, gave a 10-minute capsule summary of the Qin Dynasty, then stopped the lecture and asked students to take one minute to scan their notes and label the dynastic cycle phases. Then I projected the Qin cycle that I prepared before class and asked them to compare it to what they had done.
A friend who teaches computer science tells his students that each will be responsible for writing one line of code at the end at the end of his explanation. He gives them a minute or two to compose the code then solicits one line at a time that he plugs into a program projected for all to see. He writes what he’s given even if he knows there’s a glitch and lets his students unravel the errors to see why it’s an error.
5. Do a two-minute scenario/role play: You can do this in lectures of hundreds of students. I’ve lectured on the tactics of Joseph McCarthy and asked students to consider what their options would have been. I walk away from the podium and wade into the crowd, Oprah-like. (That alone changes the mood!) I select a random student and ask McCarthy-like questions. When he or she answers — which invariably evokes nervous laughter — I walk up to another student and ask the same questions. Then I simply ask, “OK, so what realistic options would a person have if asked such questions?” This drives the lesson home faster and harder than I could do by reciting chapter and verse.
6. Be controversial/provocative/silly: I do this when I sense that class attention is drifting. I’ll purposely shift gears and say something outrageous, wait for the ears to perk up, and then ask, “OK, so you folks tell me why I’m nuts!” For instance, during an attention lull on a lecture on Reconstruction I burst out with, “Just think how much better off the United States would have been if the Union had executed all former Confederate soldiers.” When the stupor broke I said, “Now that I have your attention, let’s brainstorm about the obstacles facing policymakers after the Civil War.” Cheap? You bet. Effective? Yep.
7. Time out to look it up: Many classrooms have wireless Internet and lots of students bring their laptops to class. You can break the monotony by taking a “look it up” break. I sometimes feign having forgotten something and ask someone to Google it; though there’s plenty I actually do forget and ask students to retrieve. Even better is to plan a pause where you can ask three or four students to look up different things you know are easily retrievable, have them report their findings, and assemble the puzzle pieces as a whole.
8. Ask affective questions: This is tried, true, and often trite, but it does get students active. Traditional Q & A is directed at obtaining a “correct” answer. In a large group that can be intimidating, but most students can tell you how something makes them feel or think. This doesn’t go anywhere on its own, but such questions break the routine and give you an opportunity to discuss applications of student affects.
9. Encourage interruptions: Let students know that questions or comments can occur anytime. Many novice lecturers fear that a question will get them off track, expose knowledge gaps, or waste time. Embrace controlled digressions. You can always stop conversation simply by saying, “Thanks for these fascinating ideas. We need to get back on task now, but let me mull over some of these things for later.” That’s also how you can handle something you don’t know if you’re not comfortable with saying, “Wow, great question and to be honest, I don’t know.”
10. End class with a question to ponder: Give a puzzle, problem, scenario, or dilemma and tell students you want to lead with that next time--the more open-ended the better. But don’t forget to start with it in the next lecture!
1. See a summary of results  on enlivening math classes.
2. University of Oklahoma Program for Instructional Innovation (See Enhanced Lecture section ).
3. Carleton College  Teaching Introductory Geoscience.
4. Cal State on interactive chemistry lectures. 
5. Boston University interactive physics demonstration.