Final answer:
The behavior of checking coin return slots on pop machines after initially finding money is an example of operant conditioning, where behavior is influenced by the consequences of past actions.
Step-by-step explanation:
The scenario of checking the coin return slot on a pop machine after finding a loonie and subsequently checking other pop machines over the next few days is an example of operant conditioning. In operant conditioning, an organism learns to associate a behavior with its consequences. The initial act of checking the coin return and finding money is a form of positive reinforcement, encouraging the repetition of this behavior in hopes of receiving more positive outcomes.