Leadership is not a fixed attribute of personality, but is a function of the group aims and values, and of the organization and techniques available for reaching a goal. Military organization involves a caste system of domination rather than a free leadership situation, yet the efficiency of operations depends upon true leadership. Group-membership, specific skills and prestige aid the battle-chosen leader, yet he may later prove ineffective in other situations. In the absence of techniques for selecting officers for special leadership jobs, the army selects for general superiority. The methods of the Australian Army Officer Selection Board included tests, clinical interviews and leaderless group tests. The best officers, judged by success in officer training schools, tend to have superior background and to be higher than average in self-confidence, sociability, and aggressiveness.