As a first step in developing a research program that united several individual strands of comprehension research, this paper describes studies that relate to the effectiveness of direct instruction. Various sections of the paper discuss the following topics: (1) variables in the direct instruction model, (2) teacher performance variables, (3) instructional design variables, (4) teaching component skills, and (5) limiting cases for strategy practice and feedback. Overall findings reported in the paper suggest that direct instruction provides a framework for analyzing comprehension instruction in terms of teaching techniques, text structures, metacognitive strategies, and specific skills. (CRH)