Keller Plan

The Keller Plan, formally the Personalized System of Instruction, is a self-paced course format devised by psychologist Fred Keller in 1968, in which students work through a sequence of short units from written study guides, take a mastery test on each unit administered by a student proctor, and move to the next unit only after passing, with lectures used sparingly as a reward rather than as the primary means of instruction. It was widely adopted in North American college science courses in the 1970s as one operational implementation of mastery-learning principles, distinct from Benjamin Bloom's own classroom-paced version of mastery learning.