There have been three distinct eras in our expectations for student learning. In Era I (1837-1909), a little learning was expected from many students. Children were to be disciplined and taught the three Rs; learning was achieved through will. In Era II (1910-1975) much learning was expected from some students, but little learning was expected from other students. The learning concept, based on early studies of intelligence, was that students differed in the capacity to learn. The capacity of students to learn was considered fixed, with little if any possibility for change in the learning capacity of poor learners. In Era III, much learning is expected from all students. The learning concept is based on recent studies showing that aptitude predicts the rate, rather than the level or complexity, of learning. This research supports the belief that nearly all students can be expected to learn at satisfactory levels given sufficient time and proper assistance. Teacher roles, evaluation, and salaries have changed throughout the three eras; the role of the principal has also evolved. In Era III fundamental changes are taking place in instruction and learning based on the concept that all students can learn and on the expectation that they all will learn. (GJ)