It has become a truism that "leadership depends upon the situation," but few behavioral scientists have attempted to go beyond that statement to examine the specific ways in which leaders should and do vary their behavior with situational demands. Vroom and Yetton select a critical aspect of leadership style-the extent to which the leader encourages the participation of his subordinates in decision-making. They describe a normative model which shows the specific leadership style called for in different classes of situations. The model is expressed in terms of a "decision tree" and requires the leader to analyze the dimensions of the particular problem or decision with which he is confronted in order to determine how much and in what way to share his decision-making power with his subordinates.Other chapters discuss how leaders behave in different situations. They look at differences in leadership styles, and what situations induce people to display autocratic or participative behavior.