Before we answer this question, we need to understand the basic difference between CLASSICAL and OPERANT conditioning. ~~~~~~~ CLASSICAL conditioning is all about ASSOCIATION. For example, imagine this: I blow a whistle, and smack you over the head with a baseball bat, right afterward. I blow a whistle again. And again, I smack you over the head with a baseball bat. If I keep doing this, what will happen, the next time you hear me blow a whistle? You'll either duck, run, scream, or beat the living s/hit out of me. Why? Because you've LEARNED the order of events. You know what happens, after I blow the whistle. That's CLASSICAL conditioning. CLASSICAL conditioning is all about making mental connections, between two things. ~~~~~~~~~~~~ On the other hand, OPERANT conditioning is all about learning from REWARD, and PUNISHMENT. Very simply.... If you do something, and as a result, something that you LIKE happens, then you've been REWARDED. And you'll probably do it again. On the other hand, if you do something, and as a result, something that you DON'T LIKE happens, then that means you've been PUNISHED. And you probably won't do it again. Do you get that? ~~~~~~~~~~~~~ So, here's a big difference between CLASSICAL and OPERANT conditioning: In CLASSICAL conditioning, you don't need to actually do anything, in order to learn. Remember my example, with the baseball bat? All you ever had to do was stand there, and let me blow the whistle, and hit you with a baseball bat. You didn't have to do anything. I did all the work, and you did all the learning. On the other hand, in OPERANT conditioning, you actually have to DO something, in order to be either rewarded, or punished. You can't get a reward, or a punishment, if you don't actually DO something yourself. You get that? ~~~~~~~~~~~ So, let's go back to your question: "In contrast to classical conditioning, operant conditioning requires _____." What OPERANT conditioning requires is ACTIVE PARTICIPATION from the learner. That means that in OPERANT conditioning, the learner has to PERFORM AN ACTION, in order to learn from it.