If you want to train a laboratory rat to pull a crank to get a food pellet, the reflex will be scratched in deeper if the creature is rewarded with some regularity but not all the time.

如果你想训练一只实验室老鼠拉曲柄去拿到一粒小丸，并定时给它一些小奖励的话，(但不是每次都一样，)那么这个小东西的条件反射会更强烈。