This technical report, authored by P. David Pearson and Margaret C. Gallagher from the University of Illinois at Urbana-Champaign, reviews the research on reading comprehension instruction. The report is divided into several sections, including existential descriptions, existential proofs, pedagogical experiments, and program evaluations. **Existential Descriptions** describe the current state of reading comprehension instruction in classrooms and educational materials. Studies by Durkin (1978-79) and Beck et al. (1979) highlight the dominance of assessment and practice in instruction, with minimal time spent on explicit comprehension instruction. **Existential Proofs** examine the impact of various variables on reading comprehension, such as prior knowledge, schema orientation, and text structure. Research by Bransford, Anderson, and others demonstrates that adult and child reading comprehension are influenced by similar factors, including schema activation and text structure. **Pedagogical Experiments** focus on specific instructional interventions. Studies by Ausubel, Bartlett, Taylor, and others explore methods to remove roadblocks to comprehension, such as providing advance organizers and pre-teaching vocabulary. These interventions show mixed results, with some studies indicating modest improvements in comprehension. **Program Evaluations** assess the long-term effects of incorporating new ideas about reading comprehension into curricula. Two projects in Honolulu and Michigan are highlighted, with one evaluating the curriculum over five years and the other over a single school year with a follow-up. The report concludes that while there is a wealth of research on reading comprehension, the effectiveness of instructional interventions is often limited. It emphasizes the need for careful definition of comprehension skills, explicit modeling, guided practice, and independent application to enhance reading comprehension.This technical report, authored by P. David Pearson and Margaret C. Gallagher from the University of Illinois at Urbana-Champaign, reviews the research on reading comprehension instruction. The report is divided into several sections, including existential descriptions, existential proofs, pedagogical experiments, and program evaluations. **Existential Descriptions** describe the current state of reading comprehension instruction in classrooms and educational materials. Studies by Durkin (1978-79) and Beck et al. (1979) highlight the dominance of assessment and practice in instruction, with minimal time spent on explicit comprehension instruction. **Existential Proofs** examine the impact of various variables on reading comprehension, such as prior knowledge, schema orientation, and text structure. Research by Bransford, Anderson, and others demonstrates that adult and child reading comprehension are influenced by similar factors, including schema activation and text structure. **Pedagogical Experiments** focus on specific instructional interventions. Studies by Ausubel, Bartlett, Taylor, and others explore methods to remove roadblocks to comprehension, such as providing advance organizers and pre-teaching vocabulary. These interventions show mixed results, with some studies indicating modest improvements in comprehension. **Program Evaluations** assess the long-term effects of incorporating new ideas about reading comprehension into curricula. Two projects in Honolulu and Michigan are highlighted, with one evaluating the curriculum over five years and the other over a single school year with a follow-up. The report concludes that while there is a wealth of research on reading comprehension, the effectiveness of instructional interventions is often limited. It emphasizes the need for careful definition of comprehension skills, explicit modeling, guided practice, and independent application to enhance reading comprehension.