Programmed instruction is a method of teaching that presents information in small, sequential steps with frequent testing and feedback. It requires students to respond actively and receive immediate feedback before advancing. The first teaching machine was invented in 1934 and programmed instruction was developed in the 1950s by B.F. Skinner, who argued that learning occurs through incremental content, feedback, and reinforcement. Programmed instruction has been used to teach many subjects and involves self-paced, self-administered lessons.