Principals wish to foster both staff motivation and student achievement in their schools, yet research reveals a seeming contradiction between these two goals. Fredrick Herzberg found in the late 1950's and 1960's that in various occupations, employees' motivation depended primarily on their sense of: the significance of their work, achievement, recognition for accomplishment, and responsibility; and on advancement opportunities. A later study corroborated these findings for teachers. Moreover, a recent study found that the "best-run" American corporations maintained excellent reputations, outstanding financial performance, and innovativeness not by hiring extraordinary people but by motivating average employees to extraordinary dedication and performance. These studies suggest that principals should motivate teachers by giving them more autonomy and responsibility. Yet school effectiveness research suggests that principals should exercise strong authority to make their schools effective. Principals thus face a seemingly irreconcilable dilemma. The solution may lie in the concept of "simultaneous loose-tight properties," which entails rigid adherence to a few broad guiding values but allows considerable autonomy in day-to-day operations. Each school should establish a unique set of guiding values through a process involving all teachers and perhaps students and parents. (MCG)