This document discusses the roles of teachers, learners, and computers in computer-assisted instruction (CAI). The teacher's role is to ensure students have the needed knowledge and skills for computer activities, set learning objectives, plan structured activities to meet objectives, and evaluate student achievement. The learner's role is to receive information, understand instructions, apply knowledge during activities. The computer's role is to act as a tutor by providing a learning environment, reinforcing learning through drill-and-practice, and providing feedback. The document also provides guidance for teachers on integrating drill-and-practice programs and describes characteristics of effective tutorial software.