Ian Pavlov was a Russian psychologist who won the 1904 Nobel Prize for his work on classical conditioning. Through experiments with dogs, Pavlov discovered that a neutral stimulus could become associated with a reflexive response through repeated pairing. Specifically, he found that dogs would salivate when food was presented, and would later salivate when a bell was rung, due to its repeated pairing with the food. Teachers can apply this concept of classical conditioning to help students learn classroom expectations, such as quieting down when the teacher approaches the board or turns on a projector.