No superior can supervise directly the work of more than five or, at the most, six subordinates whose work interlocks. The reason for this is simple.… - Lyndall Fownes Urwick

If they (the ) had not been (aware of human problems involved) — and Taylor either failed to encounter, or to recognize the significance of, the early work in industrial psychology contributed by Walter Dill Scott, Hugo Munsterberg, and others — there was the amazing fact that one of them, Frank Bunker Gilbreth, happened to fall in love with a girl who was a psychologist by education, a teacher by profession, and a mother by vocation. I know of no occurrence in the whole history of human thought more worthy of the epithet "providential" than that fact. Here were three engineers — Taylor, Gantt, and Gilbreth — struggling to realize the wider implications of their technique, in travail with a "mental revolution," their great danger that they might not appreciate the difference between applying scientific thinking to material things and to human beings, and one of them married Lillian Moller, a woman who by training, by instinct, and by experience was deeply aware of human beings, the perfect mental complement in the work to which they had set their hands.

There is nothing which rots morale more quickly and more completely than poor communication and indecisiveness - the feeling that those in authority do not know their own minds. And there is no condition which more quickly produces a sense of indecision among subordinates or more effectively hampers communication than being responsible to a superior who has too wide a span of control.

Administration has to do with getting things done; with the accomplishment of defined objectives. The science of administration is thus the system of knowledge whereby men may understand relationships, predict results, and influence outcomes in any situation where men are organized at work together for a common purpose. Public administration is that part of the science of administration which has to do with government, and thus concerns itself primarily with the executive branch, where the work of government is done, though there are obviously administrative problems also in connection with the legislative and the judicial branches. Public administration is thus a division of political science, and one of the social sciences.