In a highly competitive higher education environment where resources are limited, educators are increasingly concerned with providing evidence for the effectiveness of teaching interventions including one-to-one writing support. This article offers a model for analysing the changes in student writing as a result of individualised writing instruction. The multilayered approach to textual analysis proposed here concentrates on five aspects of academic writing that students need to master during the first year of tertiary level education. The model is illustrated with reference to a first year student's assignment. The application of the model allows for a systematic description of changes students make to their draft assignments, and the evaluation of whether these changes were consonant with the topics discussed during tutorials. The rationale for measuring student revisions is both to inform teaching and tutorial practice, and to provide valuable information for senior managers seeking to identify effective ways of enhancing students' academic literacies. (Contains 4 figures.)