There is increasing recognition of the role of self-study in building teachers' knowledge base. As teachers make decisions about what and how to teach, they draw upon a knowledge base that includes numerous types of knowledge. This knowledge base is not static, but rather changes and expands throughout one's teaching career. An important method for expanding one's knowledge base is through critical inquiry and reflection on one's practice. In this article, the author focuses on one component of her self-study: her analysis of two M.Ed. students' work in which they analyzed two of their K-12 students' work. The author's study supports research and practice in teacher education in three related areas: (1) It reinforces the notion that teaching a process differs from teaching a specified body of knowledge; (2) It underscores the importance of collaboration not only in teaching but also in assessing innovation; and (3) Documenting and sharing professors' work broadens the pool of resources for enhancing teaching and learning. (Contains 1 note.)