Charles, such disruptions are at the extreme level and of course require immediate and decisive attention. If you are in an environment where this happens more than once or is actually somewhat common then I also highly recommend always having a go to assignment that students are trained on during the early stages of any new class. Examples can include reviewing current events that relate to the topic being studied and writing a brief explanation or having student take an extra credit quiz which could be used in place of another quiz that maybe they were not able to prepare for as well. By making the quiz for extra credit it cannot harm their grade and they do not take it as a negative when you have to leave class to handle a serious disciplinary action. James Jackson