Presents a theory of school learning that attempts to explain individual differences in school learning as well as to determine the ways in which such differences may be altered. (MP)

Reports on attempts to find alternative methods of group instruction. Discusses the use of mastery learning techniques and the need to improve the students' learning processes, the curriculum and instructional materials, and the home environmental support of the students' school learning. (CMG)

Summarizes research exploring six solutions to the "2 sigma problem" of devising teaching-learning conditions that will enable the majority of students under group instruction to achieve at levels now possible only when students are tutored. Recommendations include using mastery learning, improving the home environment, and emphasizing higher…