Final answer:
Johnny learned to play quietly through shaping, which is a technique of operant conditioning that reinforces successive steps toward the desired behavior.
Step-by-step explanation:
Johnny was taught to play quietly for extended periods through a process known as shaping. Shaping is a technique used in operant conditioning, and it involves reinforcing successive approximations of a target behavior until the desired behavior is achieved. This method is particularly useful in teaching complex behaviors as it breaks down the behavior into manageable steps, making it easier for the individual to learn and demonstrate the desired behavior.
In contrast to shaping, latent learning occurs without immediate reinforcement and is demonstrated when there is a need to use the learned material. Secondary reinforcement and partial reinforcement are related to the type and scheduling of rewards, respectively, while modeling, or observational learning, involves learning by observing and imitating others.