Recommending that every state increase the duration and intensity of academic learning time (ALT) in schools, this working paper provides a rationale, discusses related research, offers guidelines for selecting and implementing activities, and describes actions schools can take to implement change. In the discussion, duration refers to the total amount of time students are engaged in learning, intensity refers to the quality of that engagement, and ALT is defined as the amount of time students are engaged in an academic task that they can successfully perform. It is asserted that research findings generally indicate the more ALT a student experiences the more the student is learning. Specific research discussed focuses on ALT and student achievement, the relationship of instructional processes and classroom environment to student learning, the distinction between allocated time and engaged time, and approaches taken to improve the duration and intensity of time used in schools. Educators are urged to (1) use existing resources to help teachers understand ALT; (2) reward exceptional students and teachers; (3) provide aides, volunteers, or tutors to teachers attempting to improve ALT; (4) implement training to improve teachers' knowledge of effective instructions; (5) reduce classroom interruptions; and (6) check for discrepancies between how time should be and actually is spent in classrooms. (RH)