Big Data knows where you’ve been and who your friends are. It knows what you like and what makes you angry. It can predict what you’ll buy, where you’ll be the victim of crime and when you’ll have a heart attack. Big Data knows you better than you know yourself, or so it claims. But how well do you know Big Data? Now, thanks to comedian and broadcaster Timandra Harkness, you can grasp the whole subject in an hour, complete with bad puns, audience participation and an electric shock machine.