The purpose of this study was to investigate social science doctoral students' preferences and needs with regard to written feedback on academic writing and to develop a written feedback categorization. In an exploratory mixed methods approach, qualitative data collected during interviews were used to form a questionnaire to collect quantitative data in two research-intensive universities. The results based on 276 doctoral students' responses provided a clear list of feedback types needed by doctoral students, including comments addressing their main idea, argumentation, clarity, and information coverage. Their preferences varied on issues of autonomy, criticism, and ambiguity, all critical factors in the transition to independence expected during their doctoral education. The resulting written feedback categorization encompasses three aspects: function, focus, and presentation. The findings of this study have the potential to guide supervisors, feedback providers, and doctoral students as well as inform further research, including instrument development and written feedback content analyses.