Hi Robert:
Good idea. Sometimes just a little "change-up" is all that is needed, like asking a question, circulating around the room, or asking students to summaize the past few minutes of class.
Other times, whole new activities will needed to reengage students who seem disinterested, unfocused, tired, or bored. Getting them and moving around or actively involved in a discussion can usually be used to capture the lost attention.
Regards, Barry
