This study examined the relationship between teacher written feedback and change in the disciplinary writing of tertiary students in their final year of undergraduate study. The student texts and teacher written feedback examined arose naturally out of a third year disciplinary-based unit in which each student submitted a text three times over the course of a semester, each time receiving feedback and a mark prior to rewriting and resubmitting. In analyzing the relationship between the different types of feedback and the changes that occurred, the feedback was categorized according to the issue that was being addressed, the manner in which it was given, and its scope. The different types of feedback were directly related to the changes that occurred in the students' subsequent rewrites. The analysis shows that certain types of feedback are more strongly related to change than other types of feedback. In addition, the analysis shows that change is further influenced by the balance between the various individual points of feedback and the degree to which they reinforce each other. The findings show that the use of feedback that is strongly related to change can improve the writing of students in the disciplines. (Contains 4 tables and 1 figure.) [Note: The publication year (2009) shown on the PDF is incorrect. The correct publication year is 2008.]