Audience manipulation at its most pathetic; it happens not only with canned laughter but also when imbedding a particular man or woman among live audiences. Uncertain of the humor or delivery of the dialogues, producers will shamelessly induce, at least, giggles - hit shows included. Listening closely to the laughter even with 'Cheers' and 'Seinfeld', there will be occasion to recognize the regular presence of someone's guffaws to provoke laughter.