This case study follows a teacher candidate through her semester of student teaching English in a suburban high school in the U.S. Southeast. The study is part of a line of inquiry that investigates the factors that contribute to teachers' development of "concepts" to guide their instruction. In particular, this research focuses on the mediational role of "settings" in teachers' development of a teaching conception and the "attributions" made by the teacher candidate to the sources for her understanding of how to teach. Data for the research consist of observations and interviews with focal teacher Anita and key stakeholders. These data were analyzed to identify the "pedagogical tools" used during student teaching and the sources to which she attributed her learning of them. Findings indicate that Anita's initial conception of teaching was complicated by competing centers of gravity--that is, settings with conflicting notions of effective practice--that pulled her in many different directions, thus making her ability to develop a coherent approach to teaching a challenge. The study concludes with a discussion of conventional linear views of concept development and how attention to the settings of learning to teach can help explain the difficulties of learning to teach in cohesive and consistent ways. (Contains 4 tables, 4 figures, and 1 note.)