Book excerpt: The SAGE Encyclopedia of Educational Leadership and Administration presents the most recent theories, research, terms, concepts, ideas, and histories on educational leadership and school administration as taught in preparation programs and practiced in schools and colleges today. With more than 600 entries, written by more than 200 professors, graduate students, practitioners, and association officials, the two volumes of this encyclopedia represent the most comprehensive knowledge base of educational leadership and school administration that has, as yet, been compiled.