This book explores the concepts and techniques of data mining and machine learning, a promising and flourishing frontier in data and information systems and their applications. this book provides the background necessary in these areas in order to facilitate the reader¿s comprehension of their respective roles in data mining. Rather, the book is a comprehensive introduction to data mining, presented with effectiveness and scalability issues in focus. This book presents an overall picture of the field, introducing interesting data mining techniques and systems and discussing applications and research directions. An important motivation for writing this book was the need to build an organized framework for the study of data mining¿a challenging task, owing to the extensive multidisciplinary nature of this fast-developing field. We hope that this book will encourage people with different backgrounds and experiences to exchange their views regarding data mining and machine learning so as to contribute toward the further promotion and shaping of this exciting and dynamic field.