Answer:
The introduction of an approach which modified behaviour using short lectures and self-paced learning was developed by Fred Simmons Keller. It was called Personalized-Proctorial System of Instruction (PSI).
Step-by-step explanation:
He designed a system which delivered and monitored the progress of assimilation of the ideas that were being taught unit by unit.
Students were required to master one unit before exposure to the next.
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