Hi Erik: Great plan and smart on your part. The trick is to make sure whatever is added or substitued as a back-up is relevant (which you say your lessons are) to the current topic. A variation of what you're doing is get your students into groups and have them dig out assigned information, then have the group write out 2-5 questions. You can then use these (or their essence) to make a quiz. Yes, some students will recognize their question(s), but they'll have earned the points from the studying they had to do to be able to create those questions. Regards, Barry