Accidental Reinforcement

Accidental reinforcement is a coincidental (and unintended) pairing of of a stimulus and response. This can happen in a lab when a test animal associates a particular handler with something positive (being paid attention to or petted) and responds to their appearance (as in classical conditioning) or when the animal happened to be on an exercise wheel when food was provided, leading to more time spent on the wheel in hopes of being fed again (as in operant conditioning).