Praise, help, or even a look, may be enough to interrupt him, or destroy the activity. It seems a strange thing to say, but this can happen even if the child merely becomes aware of being watched. After all, we too sometimes feel unable to go on working if someone comes to see what we are doing. The great principle which brings success to the teacher is this: as soon as concentration has begun, act as if the child does not exist. Naturally, one can see what he is doing with a quick glance, but without his being aware of it.