This book deals with the implementation and application of the "in the best interests of the child principle" in research and practice. With contributions by authors from nine different countries (United States, Belgium, France, Norway, The Netherlands, United Kingdom, Israel, Ireland, Canada) an international perspective is adopted. After the outline of the theme given in the introductory chapter, the first part illustrates the search for theory-driven and empirically-based models to deal with the complexity of parenting. In the second part illustrations about the implementation and application of the best interests principle in child and youth care practice are given. Part three is focusing on the organization of child and youth care systems according to the best interests principle.