On the premise that teacher decision making significantly influences instructional effectiveness, this study gives some insight into the decision-making process that shaped the course of reading instruction in four elementary teachers' classrooms. During one school year, the fieldwork method of research was used to discover the decisions teachers made and to describe how these decisions were reflected in their classroom practice. The four teachers made decisions on testing, grouping, materials, and management within the first month of school. After observing and reflecting on the decision-making process and through discussion with the teachers, it was concluded that the underlying purpose of decision making was not to instruct students but to manage them effectively. (Author/JD)