worldwide

Fg9Wz8BPEhX - interesting, 8,280 out of about 82,800 students earned a earned a Statement of Accomplishment for Coursera's Gamification class. It wasn't 'difficult', but you had to watch the lectures to pass the quizzes and there were 3 peer graded written assignments, so you had to put in some effort to pass. 10% is really a lot.