great teachers tended to set big goals for their students. They were also perpetually looking for ways to improve their effectiveness.

Superstar teachers had four other tendencies in common: they avidly recruited students and their families into the process; they maintained focus, ensuring that everything they did contributed to student learning; they planned exhaustively and purposefully—for the next day or the year ahead—by working backward from the desired outcome; and they worked relentlessly, refusing to surrender to the combined menaces of poverty, bureaucracy, and budgetary shortfalls.

Asking “Does anyone have any questions?” does not work, and it’s a classic rookie mistake.

His predictions for the fate of print media organisations have proved unnervingly accurate; 2009 would be a bloodbath for newspapers, he warned – and so it came to pass.

"Look, we got erotic novels, first crack out of the box, once we had printing presses. It took a century and a half for the Royal Society to start publishing the first scientific journal in English. So even with the sacred printing press, the first things you get serve the basest human urges. But the presence of the erotic novels did not prevent us from pressing the printing presses into the service of the scientific revolution. And so I think every bit of time spent fretting about the fact that people have base desires which they will use this medium to satisfy is a waste of time – because that's been true of every medium ever launched."

Shirky does not own a television. Americans watch, collectively, two hundred billion hours of television a year, and if online social media diverts even just a fraction of that time, he argues, that has to be a good thing. "As I say in the book, even the stupidest possible creative act is still a creative act. And I'd still take the most inane collaborative website over someone watching yet another half hour of TV."