Why is it hard to know if you are making a difference in public services? What can you do about it? Public services throughout the world face the challenge of tackling complex issues where multiple factors influence change. This book sets out practical and theoretically robust, tried and tested approaches to understanding and tracking change that any organisation can use to ensure it makes a difference to the people it cares about. With case studies from health, community, research, international development and social care, this book shows that with the right tools and techniques, public services can track their contribution to social change and become more efficient and effective.