Teaching and Classroom Practice Galindo, E., & Newton, J., (Eds.). (2017). Proceedings of the 39th annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education. Indianapolis, IN: Hoosier Association of Mathematics Teacher Educators. 1250 STORIES OF AGENCY: DO GRADUATE STUDENTS PERCEIVE THEMSELVES AS PART OF THE MATHEMATICAL COMMUNITY? Mollee Shultz Patricio Herbst University of Michigan University of Michigan mollee@umich.edu pgherbst@umich.edu Graduate student teaching assistants (GTAs) are responsible for the instruction of undergraduate students in critical introductory courses, but are not yet in the position of professors. Given their unique status, we ask if there are differences in how graduate students and professors express their agency when speaking about their responsibilities and how graduate students position themselves as members of the community of mathematicians. We use tools from systemic functional linguistics (Halliday, 1994) to analyze 16 interviews with graduate students and professors from research I universities. We found important differences in how graduate students and professors perceive their agency, and agency varies according to whether it concerns disciplinary or institutional responsibilities. Future research can investigate how to create more opportunities for developing the agency of GTAs in institutional decisions. Keywords: Post-Secondary Education; Affect, Emotion, Beliefs, and Attitudes Each year approximately 743,000 undergraduate students enroll in calculus courses and 834,000 enroll in introductory level courses (e.g., pre-calculus) taught in mathematics departments (Blair, Kirkman, & Maxwell, 2013). In some departments GTAs are only responsible for leading recitations and grading, but in other departments they teach over a third of all course offerings (Lewis & Tucker, 2009). Graduate students benefit from the experience because teaching is an aspect of being a mathematician, the community into which they are entering. As Lave and Wenger (1991) stressed, teaching and learning do not only occur in an individual’s mind, but rather are mediated by social situations in a community of practice. Teaching positions, as part of the graduate education, assist in the socialization of graduate students into the faculty positions they may eventually take (Austin, 2002). However, GTAs have little to no experience and are given little training. Preparation programs range from a few hours’ orientation to weeklong workshops (Ellis, Speer, & Bookman, 2016). How can we support the apprenticeship into teaching for graduate students while fostering quality instruction? This study seeks to understand differences between how professors and GTAs perceive and manage their roles as instructors. We compare their social positioning and agency. Researchers have noted the significance of agency, or “who has control over the way mathematics is done and expressed” (Wagner, 2007, p. 36), for the doing of mathematics in the context of voice in textbooks (Herbel-Eisenmann, 2007; Herbel-Eisenmann & Wagner, 2007; Morgan, 1996) and in classroom discourse (Wagner, 2007). Previous research has addressed teacher and student agency in their interactions with each other and the discipline, but it has not addressed agency in two key areas: comparing agency of different groups of teachers and comparing agency in different aspects of teaching. We will compare graduate students and professors in two aspects provided by our theoretical framework. Theoretical Framework Herbst and Chazan (2012) proposed a framework of four professional obligations that mathematics teachers must respond to as professionals: towards representing the discipline of mathematics appropriately (disciplinary), treating individual students as persons with unique assets and needs (individual), creating a socially and culturally appropriate environment for students to share space and resources in a class (interpersonal), and respecting institutions such as the school,