What a valuable tool! It is amazing how such a subtle response to a difficult student can yield such drastic results. When words sometime fail, simple proximity can work great. Walking next to their desk, flashing a smile while lecturing has been very useful for me. But, what about the student who doesn't care? The rare student who continues to talk, text, etc? In the adult learning realm what do you do with extreme behavior? Send them to the principal? This is a dilemna that I have fortunately not run into yet, but have wondered about for awhile. Any thoughts on serious behavior issues?