This, from Kurt Ralske, is my favorite assignment from Draw It With Your Eyes Closed: The Art of the Art Assignment:
"I was frustrated with a class that seemed to be making work that was just too easy. Too many conceptual one-liners, too many lightweight "political statements" devoid of any ambiguity, too much autopilot minimalism. No risk, no complexity, no real personal investment.
My assignment was make a piece that is guaranteed to make the viewer say, ‘WTF?!?’
Not every response was a masterpiece, but at least students stopped relying on their default can’t-fail strategies. ‘WTF?!?’ is actually a much humbler goal than changing the world or manifesting mystical truth. To aim low was liberating. For some students, the pleasure they experienced in completing the assignment served as a reminder that making art does not always have to rely on strenuous efforts toward a precisely predetermined goal. Instead, sometimes the process can be only a playful exploration, destination unknown. Feedback to this assignment was strongly positive. Several students reported they felt that WTF-ness was exactly what had been missing from their work.”