Hi David: Being proactive helps us get a leg up on important information where students performance levels are. Your experience ceratinly underscores that. As most of us are busy, we tend to depend and assume too much sometimes. What I've learned is if I'm the guy responsible for the class, I need to be accountable to my students, so I'm going to go out of my way to get information. I ask questions, verify, double check, avoid procrastination, and work hard at understanding what could wrong, then try to do what I can to prevent that from happening. Still, errors, mistakes, snafu's, and assumptions plague even the best laid plans. But more agressive responsibility can help minimize it. Regards, Barry