This book is a collection of essays on mastery learning, which is defined as an instructional philosophy that asserts that under appropriate instructional conditions virtually all, rather than some, students can learn most of what they are taught. The articles in this book are based on a symposium. Social scientists were contacted and asked to respond to the following question from the standpoint of their particular discipline: "If mastery learning could be successfully implemented, then what would be the implications for the school and society?" The book is divided into two parts with three essays in each part. Part 1 focuses on the "if" portion of the question. It is intended to introduce the reader to the current state of mastery learning theory, practice, and research and to set the stage for part 2. Part 2 centers on the "then" portion of the question. It is intended to sketch out some of the theoretical implications of mastery learning and to highlight some of its practical administrative implications. (JA)