Most Americans believe residents -- doctors in training who work at teaching hospitals -- put in far fewer hours than they actually do, a new survey has found. And people also told the pollsters they would want to know if the doctor treating them has been on the job for 24 hours so they could ask for a different caregiver. Dr. Charles Czeisler of Brigham and Women's Hospital and his colleagues report today on a telephone survey that asked people how many hours they thought resident physicians worked in a single shift and over the course of a week.