Job satisfaction, defined as spending a high percentage of time on activities that many people would consider rewarding or pleasant. Training difficulty, defined by the length of training typically required, adjusted by the amount of science and/or math involved. Prestige, based on an informal survey of college-educated adults. Job market outlook, based on data from the U.S. Department of Labor and professional organizations, with the career's resistance to being offshored considered. Pay, with data provided by payscale.com, which has an extensive database of individual employee compensation profiles.