The Keller Plan (also called The Personalized System of Instruction) is an instructional method introduced by Fred Keller, J. Gilmour Sherman, and other researchers in the 1960s.¹⁾ This individualized learning method was oriented on improvement of high school learning.

Keller's idea was to make higher education teaching more adjusted to individual needs. His method was first introduced in 1962 in order to help establishing a Department of Psychology at the University of Brasilia and design a course for the students. After additional modifications, the key aspects of his method can be described as follows:²⁾

• Go-at-your-own-pace. A student can move through the course content at his own pace.
• Strict definitions of learning objectives.
• Unit-perfection requirement. In order to advance to the next unit, a student needs to demonstrate mastery of the preceding unit.
• Emphasis on written materials. The emphasis is on learning from written materials. Lectures and demonstrations will be provided only when you have demonstrated your readiness to appreciate them; no examination will be based upon them: and you need not attend them if you do not wish.³⁾
• The use of proctors. Proctors enhance the social aspect of educational process, enable repeated testing with immediate scoring and tutoring.