There are numerous reasons why children lose control. And there are times when children lose control as a group. Adults monitoring or working with an out of control group have many proactive strategies available to them that may include interactive modeling, engaging content, and clear expectations. For those times when that seems not to be working there are alternatives to threats and screaming.
I have found myself in situtaions where I walk in and my students are screaming, running around, or doing other off-task behavior in the presence of an adult. When this happens, the best thing to do is to immediately stop the misbehavior. This can be tricky because I am one who does not like stepping on the toes of another adult. However, the most important thing is to help the children regain their self control.
During these times a strategy I use is redirection. If I walk in and find my students engaging in off-task behavior that clearly demonstrates they are our of confrol I give a clear direction for them to do something else. That may be to sit down or come to the rug. It may be to take out a book to read. I may even begin singing a relaxing song and get them to join in. None of these are rewards. And none are punishments. Because my goal is to stop misbehavior and help them regain their self control and engaging them in a calm task will help to do this.