James M. Kouzes and Barry Z. Posner are the bestselling coauthors of The Leadership Challenge, A Leader's Legacy, Credibility, Encouraging the Heart, and The Leadership Challenge Workbook, and over a dozen other books and workbooks on leadership. They also developed the highly-acclaimed Leadership Practices Inventory (LPI), a 360-degree assessment tool based on The Five Practices. They are among the most sought-after scholars and educators on the subjects of leadership and leadership development.