I'm sure this has been covered here before, but I couldn't find it through a search. What do you do when a student is "sure" they turned something in but you just don't have it? I usually ask them to "double check" their folder or notebook, and often times that's where it turns out to be, but what's the fair solution when it's not there? I know it probably depends on the student and the importance of the work, and right now I have 2-3 students adamantly insisting that they turned in fairly significant assignments that I can find no trace of. I've watched them look through their folders and notebooks, and I've looked several times through every place they could possibly be. I'm doubtful that I lost them, but I can't be 100% sure. What would you do?