L2 student–U.S. professor interactions through disciplinary writing assignments: An activity theory perspective

• Activity theory helped to understand student–professor concurrent learning.
• Participants enacted agency in disciplinary writing and teaching practices.
• Participants exerted mutual influences on each other's activity systems.
• Activity system networks helped to see participants’ learning beyond the course.

This study aimed to explain the complexity involved in multiple agents’ learning in interaction in graduate disciplinary writing contexts. Adopting activity theory (Engeström, 1999) as a guiding framework, I analyzed interactive experiences between an L2 English student writer and his professor regarding different writing assignments in a U.S. graduate course. Sources of qualitative data through one semester included interviews, a class observation, and written documents. The semilongitudinal nature of the study illuminated both participants’ changes in their writing and teaching practices over time.Activity theory enabled the visualization of the participants’ experiences with each assignment as an activity system. Moreover, the concept of interacting activity systems or activity system network offered a useful perspective to understand concurrent and multi-directional learning between the student and the professor, who mutually shaped and influenced each other's writing and teaching practices. The study's findings provide encouragement for L2 English students in terms of their potential power to bring change to their professors’ teaching practices and their L2 disciplinary communities. Furthermore, through the lens of activity theory, the study offers future possibilities of exploring L2 graduate disciplinary socialization by investigating different genres as activity systems and learning in multiple directions among students.