Keeping a Lecture Hall Awake

The case for interrupting yourself

Breaking up a lecture with questions is not just a way to keep people awake. In the largest review of the question so far, Scott Freeman and colleagues combined 225 studies of undergraduate science, engineering and maths courses. Students in classes with active learning did better in exams than students taught by traditional lecturing, and students in the lecture-only classes were about one and a half times as likely to fail.

Active learning covers many techniques, but the simplest is the one that fits a big hall best: stop every so often, ask everyone a question, and act on the answers.

Two hundred people in, in two minutes

In a big room, joining has to be instant or the activity dies before it starts. Students need nothing installed and no account. They go to giga-quizzes.com/play and type the six-digit room code, or point their phone camera at the QR code on the projector; one game takes up to 500 players. For a weekly course, put a join link in the course page before the lecture: clicking the big room code in the lobby copies a link with the code already in it.

Leave the QR code up for a minute or two while people settle. Once everyone is in, the padlock in the top bar stops anyone else joining, so a code shared on social media cannot bring in people from outside the hall; press it again for a latecomer.

Ask concept questions, not recall questions

The best lecture question makes students apply an idea, not repeat a definition. If the answer could be copied from the slide that was just shown, it tells you nothing.

Build the wrong answers from the mistakes students actually make. The chart at the reveal then shows you not just how many understood, but what the rest believe instead.

A worked example

After ten minutes on elasticity, an economics lecturer asks: the price of salt doubles; what happens to how much salt people buy? It falls a little, it halves, it stays exactly the same, or it rises.

The right answer is that it falls a little. Salt is cheap and has no close substitute, so demand for it is inelastic. A third of the room chose “it halves”, which tells the lecturer something precise: those students are treating every good as if its demand moves one-for-one with price. That is a two-minute fix now, and an exam answer saved later.

Ask, discuss, ask again

When a concept question splits the room, the most effective next step is often not to explain it yourself. Eric Mazur’s peer instruction, refined over ten years of physics teaching at Harvard and described by Catherine Crouch and Mazur, works like this:

1. 1Everyone answers alone, without discussion.
2. 2If the answers are split, do not reveal the right one.
3. 3Students turn to a neighbour, ideally one who answered differently, and try to convince each other for two minutes.
4. 4Everyone answers the same question again.

The second vote is almost always better than the first, and the hall fills with students explaining ideas to each other. Many lecturers use a rough rule for when to do this: if nearly everyone is right, confirm and move on; if hardly anyone is, reteach; anywhere in between is where discussion pays off most.

Polls to check the room

Not every question needs a right answer. A quick poll after a hard section tells you how the room feels without anyone raising a hand in front of two hundred people.

• “How clear was that last section?” From crystal clear to lost me.
• “Which of today’s topics should I go over again next week?”
• “What is still confusing? One word.” Typed answers become a word cloud.

Only totals reach the screen, so students are honest in a way they never are with a show of hands.

Settings for a big room

A few switches in Game settings matter more in a hall than in a classroom. Leave Phones show colors only off, so every student reads the question on their own phone; from the back row, the projector is hard to read. Switch on Reveal answers after 3s, so everyone reads the question before anyone can answer. Keep Filter nicknames on, which swaps a rude nickname for a neutral one before it reaches the screen. And switch off Auto-advance screens, so one set with a question or two per section can run alongside the whole lecture, waiting for you between sections.

After the lecture, the report shows how the hall answered every question, which tells you where to start next week. For a revision session before an exam, a self-paced format such as Hacker mode suits a big room surprisingly well: everyone answers at their own speed, and nobody waits for anyone.