Over the past 40 years, considerable progress has been made in our understanding of the aetiology 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 presents 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 we have 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 goes on to consider how models are used in our understanding of child abuse, focusing on three major paradigms (sociological, psychodynamic, 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. Copyright © 2001 John Wiley & Sons, Ltd.