Well for me, I think i'd say CAT TRAINING.
Here's an example. My newest cat is still learning how to come to the food in the kitchen, and come at times when she needs to eat even if already eaten in the morning.
So before today, I've been trying to get her to come just by placing the food down. But she doesn't give a response to it. Next I try a bell alone, and some other jingling or noise makers. Still no response of her coming to me at all. Then I tried placing the food down while ringing the bell, she's starting to understand, but still not a very good response. I assume in a few more days, she will understand that the bell/other noise means COME TO ME. That is a conditioned response i'm hoping to get soon.