Writing transfer research often illuminates the writing abilities, attitudes, and assumptions college writers bring to a writing assignment, but faculty members across the disciplines may not have the tools for understanding what the students in their particular classes bring to their particular writing assignments. In this proposed model, students respond to a series of reflective prompts before, during, and after completion of a major upper-division writing assignment. Faculty members then reflect on how these responses might change the way they assign writing and teach course content. The disciplinary and course-based threshold concepts emerging from this process suggest a dynamic and situated approach that both facilitates faculty understanding of transfer and offers a method for responding to it.