This book presents a holistic overview of user engagement, which has become an increasingly important subject for a variety of industry and academic fields, including engineering, computer science, and information science. The author begins with a definition of user engagement and an explanation of the theoretical background of the topic. The book then covers methodological approaches and examines some of the broader factors that influence user engagement. The author explains methods for measuring user engagement and evaluates the efficacy of each one. The book includes examples from recent research studies throughout, describing user engagement in different settings with a variety of digital information systems.