When a dog is rewarded for selecting an article that smells like peanut butter, which learning method is being applied?

The method being applied here is positive reinforcement. This learning process involves providing a reward following a desired behavior to increase the likelihood of that behavior being repeated in the future. In this scenario, the dog is rewarded for successfully selecting an article with the scent of peanut butter, which reinforces the behavior of choosing that article associated with the desired scent. This effectively encourages the dog to continue making that choice in similar situations.

Positive reinforcement is a powerful tool in training because it strengthens the bond between the dog and trainer, fostering a positive learning environment. The use of a palatable reward, such as peanut butter, makes the learning experience enjoyable for the dog, ensuring that the behavior is not only learned but also motivated by the reward provided.

Other options such as extinction, negative punishment, and positive punishment involve different mechanisms which do not apply in this context where an affirmative reward is given for a behavior.