Over the past 40 years considerable progress has been made in the understanding of the etiology and processes of child abuse. This understanding has been based within two scientific paradigms: the psychodynamic and sociological models. More recently, both strands have been incorporated in a more comprehensive "ecological" paradigm. This paradigm views child abuse as occurring within the context of the child's environment at different, nested levels. The ecological paradigm is currently the most comprehensive model available for understanding child abuse, providing a systematic framework in which to conduct both research and child protection practice. This paper begins by describing the nature and use of scientific models in both research and practice. Three levels of models are outlined: working models, paradigms, and worldviews. The paper then considers how models are used in understanding child abuse, as it focuses on three major paradigms (sociological, psychodynamic, and ecological). The ecological model or paradigm is then described in detail, expounding the four different levels within it. The uses and limitations of the ecological model are discussed in relation to both research and practice. Finally, some practical suggestions are provided for the reader to creatively apply this understanding at a personal and professional level. 3 figures, 1 table, 21 references, and a glossary