A study investigated the impact of direct instruction on reading comprehension strategies and the degree to which cooperative learning processes enhance students' learning of strategies. Subjects, 486 third- and fourth-grade students in four elementary schools from an ethnically diverse school district in a medium-sized city in central Pennsylvania, were assigned to instructional treatments on strategies for identifying the main idea of passages. Treatments involved cooperative learning with direct instruction, direct instruction alone, and a traditionally instructed control group. Both groups who received direct instruction on main idea strategies performed significantly better than did the control students in identifying main ideas of passages. Students who also used cooperative learning processes to summarize and explain the strategies to one another performed significantly better than did the students who received only direct instruction on the strategies. (Three tables of data are included; 38 references are attached.) (Author/RS)