Transforming Writing was a two-year action research project, sponsored by the Esmée Fairbairn Foundation, which developed a model for the teaching and learning of writing that embedded formative assessment. This report evaluates to what extent the model of writing developed by the teachers during the research period impacted on children's writing in terms of attainment, confidence and engagement. It also evaluates the effectiveness of a training model to spread the approaches to other teachers within the participating school, which was developed in the second year. The evidence suggests that the focused use of formative assessment by teachers with children and by children with peers can make a major difference to children's writing progress in terms of attainment, engagement and confidence. It also suggests that the model of training effectively supports dissemination of Transforming Writing approaches to other teachers. The following are appended: (1) Glossary; (2) Explanation of the 12 classroom approaches; (3) Control group--additional charts; and (4) Impact on children's confidence and engagement--additional charts.