Yet people of high effectiveness are conspicuous by their absence in knowledge jobs. High intelligence is common enough among knowledge workers. Few people of effectiveness were needed: mainly those at the top who gave the orders that others carried out. In fact, only a small fraction of the knowledge workers of earlier days were part of an organization. The realities of the knowledge workers’ situation both demand effectiveness from them and make effectiveness exceedingly difficult to achieve. Effectiveness thus deserves high priority because of the needs of organization. It deserves even greater priority as the tool of the executive and as his access to achievement and performance. Effective people, in other words, differ as widely as physicians, high-school teachers, or violinists. Effectiveness, in other words, is a habit; that is, a complex of practices. And practices can always be learned. Practices are simple, deceptively so; even a seven-year-old has no difficulty in understanding a practice.