Skinner develops the 'Skinner Box' (also known as an operant conditioning chamber), an apparatus designed to study animal behavior in a controlled environment. This device allows for precise measurement of responses and the systematic manipulation of reinforcement schedules.

Through his experiments with the Skinner Box, Skinner formulates the principles of operant conditioning. He identifies the roles of reinforcement (positive and negative) and punishment in shaping behavior. He observes how different schedules of reinforcement affect the rate and pattern of responses.

Skinner publishes 'The Behavior of Organisms,' which presents his experimental analysis of behavior and outlines the basic principles of operant conditioning. This book becomes a foundational text in behaviorism.

Skinner and his colleagues continue to research and refine the concept of reinforcement schedules. They investigate the effects of fixed-ratio, variable-ratio, fixed-interval, and variable-interval schedules on behavior, revealing how these schedules produce different patterns of responding.

The principles of operant conditioning are applied to various fields, including education, therapy, business, and animal training. These applications demonstrate the practical utility of Skinner's theories in shaping behavior in real-world settings.