The '3D' model of literacy pedagogy and practice was initially conceived as a way to understand the multidimensionality of subject-specific literacies, with respect to writing, curriculum and pedagogy. The model was subsequently revised for thinking around literacy and technology. As a model it has been highly influential in literacy research and education in Australia since it first appeared in 1988. However, until now there has not been available a single, extended account of the model, its genesis and evolution, across a range of fields and for a variety of purposes. This book provides a coherent, practical-theoretical account of the model, with specific reference to literacy education and schooling in the 21st century.