This document provides an overview of programmed instruction, self-directed learning (SDL), computer-assisted instruction (CAI), and e-learning. It defines each topic and discusses their characteristics, principles, types, advantages and limitations. Programmed instruction breaks content into small steps and provides feedback, while SDL emphasizes learner ownership and self-management. CAI uses computers to deliver instruction through various modes like tutorials and simulations. E-learning utilizes online resources and internet connectivity for distance learning.