The knowledge, beliefs, and attitudes teachers hold about themselves, the students they teach, and the world around them are important in understanding how teachers cope, adapt, instruct, and manage classrooms. In particular, teachers’ beliefs influence their perceptions and judgments and subsequently drive what they do in the classroom. Further, beliefs and attitudes are a crucial component in processes of change. Numerous factors influence the development of a teacher’s knowledge, beliefs, and attitudes. Personal influences (e.g., life experiences, beliefs about self and others), schooling (e.g., experience observing and participating in classrooms, well-established beliefs about teaching), and formal knowledge (e.g., content knowledge, pedagogical knowledge) are all avenues through which teachers acquire and develop their knowledge and perceptions of teaching, schools, and students.