Data for this analysis of classroom instruction were part of the junior high phase of the Managing Academic Tasks (MAT) study (Doyle, Sanford, Clements, French & Emmer, 1983). The MAT focuses on the character of academic tasks, the nature of the overall task systems that operate in classrooms, and the contexts associated with task accomplishment. The MAT is based on a definition of curriculum as a set of tasks students accomplish. The role of active content instruction in the task systems of four junior high school classes, two in science and two in English, was examined. Case descriptions focus on the circumstances and nature of observed instruction, its relation to students' work, cognitive focus, pedagogical strategies, and problems teachers appeared to encounter in conducting instruction. Analyses suggest that instruction and instructional problems should be considered in the light of the tasks in which instruction is embedded. It is suggested that the concept of content instruction as a resource for student task accomplishment might serve as a useful way for secondary teachers to think about their teaching. (Author/JD)