That you overrun your time slot. This is upsetting to conference organizers, and to all the speakers who follow you. It can also stress out your audience. Don’t do it. The only antidotes are to A. Try out the talk several times to be sure it can indeed be done within the time limit. If not, you must cut material. B. Be disciplined about watching the clock and know how far you need to be when half of your time has gone by. C. Prepare a talk that is no more than 90 percent of your time limit.
