The present bounded case study explored preservice teachers' experiences using a boundary object in the form of a mathematics course assignment during a pre-student teaching clinical experience. The study focused on preservice teachers' perceptions of how utilizing a boundary object influenced the dynamics of their hierarchical relationships with their cooperating teachers, their approaches to teaching mathematics while at their placement, and their abilities to negotiate between their teacher education programs and clinical experiences. The research questions asked: How, if at all, can a mathematics course assignment from a teacher education program serve as an effective boundary object to (1) impact the power dynamics between preservice teachers and their cooperating teachers, (2) limit the default adoption of cooperating teachers' teaching styles in mathematics, and (3) support preservice teachers as they navigate complex negotiations between their teacher education courses and clinical experiences? The study included nine preservice teachers enrolled in an Elementary and Middle Education Program at a large, midwestern, urban university. Data sources included questionnaires, course assignments, interviews, and focus groups. Findings suggest that a boundary object in the form of a mathematics course assignment (a) provided preservice teachers with a greater sense of power in their relationships with their cooperating teachers, (b) facilitated an opportunity for preservice teachers to deviate from their cooperating teachers' teaching styles and implement teaching practices more closely aligned with their own ideal style, (c) provided preservice teachers with a crucial opportunity to practice ambitious mathematics instruction they intended to use in their future classrooms, and (d) helped to bridge preservice teachers coursework and clinical experiences. Given the study findings, it would be beneficial for teacher education programs to incorporate assignments designed to serve as boundary objects to help facilitate valuable and productive field experiences for preservice teachers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]