After you've done this a few times, you may see the animal visibly startle, look towards the treat, or look to you. This indicates that she's starting to form the association. The click sound becomes a signal for an upcoming reinforcement. You can read more about Pavlov and classical conditioning at Dr. Kendrick's Learning Theories Lectures website . Operant Conditioning Classical conditioning forms an association between two stimuli.
Operant conditioning forms an association between a behavior and a consequence.
There are four possible consequences to any behavior. Consequences have to be immediate, or clearly linked to the behavior. With verbal humans, we can explain the connection between the consequence and the behavior, even if they are separated in time. For example, you might tell a friend that you'll buy dinner for them since they helped you move, or a parent might explain that the child can't go to summer camp because of her bad grades. With very young children, humans who don't have verbal skills, and animals, you can't explain the connection between the consequence and the behavior.