Hattie and Timperley's (2007) model of effective feedback, widely used in teacher professional development, provides an easily-applied framework for thinking about the information contained in feedback. However, the model simplifies a complex phenomenon shaped in practice by interpersonal, disciplinary and institutional aspects. Examining the model in practice reveals links between the types of information offered and their context, highlighting the advantages of using the model strategically. This paper reports a qualitative study of four Australian secondary English teachers' written feedback. Teachers' annotations on student texts were analysed using Hattie and Timperley's model. Combining this analysis with interview data demonstrates how teachers' targeting of thinking levels is linked to assessment practices, cultural tools and their own beliefs about feedback and learning. The study underlines the need to invite teachers to consider how their context shapes their application of the model.