Michael, JV... great comments!

For Craig:

We have to remember that as magicians our job isn't top merely "display" the effect, but to take an active roll in directing the audience's attention away from the actual method. This is very difficult in this particular case as it is a physical effect that is obvious upon examination of the boxes themselves. In other words... they figured it out because you allowed them to.

Many times amateurs will perform an effect, then wait for people to talk about it until many times... a solution is reached. We should keep their minds occupied to prevent not only discovery but even taking the path to discovery. This might require leading the conversation to another topic, effect or problem that is more unsolvable. The old rule for me is never close with a "puzzle". Otherwise they will just sit and think about it until a solution is reached.

Michael, your points are well taken, especially about Doug's ability to see and exploit the anomalies in life that we all take for granted. Certainly a unique perspective! Thanks for weighing in on this discussion.
JNeal