Dan asks the class whether any of them has ever checked the weather on their phone to see if it’s likely to rain while they’re outside. Everyone has.… - David Franklin

The students are asked to rate their level of surprise on a five-point scale from ‘not surprised at all’ to ‘beyond shock’. Many describe feelings of total shock and numbness: a large majority indicate some level of surprise. He asks them: “Why were you surprised?

I’d like anyone who was born on March 22nd to stand up.” Two students stand up. They link eyes from across the room, and smile. The room laughs. “Now, anyone born on June 14th.” Another two stand up. The room laughs again. “Now, anyone born on August 2nd.” Two more: the class is laughing at each pair, and re-examining their original takes on how low the probability was likely to be. They are learning through experience about human fallibility with estimating probabilities, and at the same time learning something about their classmates. “How about December 21st?” This time, three students stand up. This gets a big laugh for two reasons: firstly, it is unexpected, and secondly, it helps to ram home the idea that in a class that size (there are about 3,000 pairs in a class of 80), there are likely to be “coincidences” everywhere.

So Trump was 29% likely to win. What does 29% mean?” he asks. This is an odd question for many: they’re doing a Master’s degree at Harvard, and they’re being asked what a percentage means. The question is aiming at the gut reaction of the brain to the number. Inevitably, students think it might be a trick question. Dan waits a while, and when no-one raises their hands, he breaks away from the example to tell a story: “You know, when I first started teaching, I was terrified of silence. I thought, ‘oh my god, I’ve got to do something, they’re not saying anything’.” The class laughs: he has eased the tension created by the silence. “The more I taught, the more I realised that silences are important in a class – they give time for people to think. These days, I’m not afraid of silence at all.” After a few seconds, a woman puts up her hand. “Well, obviously, I knew that it meant there was some chance that he would win. But it was still a shock that the 29% happened.