from Inside Higher Ed:
Bad lecturers violate nearly every rule of good communication. They never vary voice timbre or pitch. They either stare at their notes or ignore them altogether and ramble onto whatever topic comes to mind. They never make eye contact with their audience or use visual aids and handouts. Everything comes out at the same speed, and they never, ever show the slightest bit of life when discussing the very subject that supposedly excites them. Check for a pulse; if you can stay awake!