Choose your adventure is just that. A puppy - or a dog - learning that he can choose reinforcement or he can choose no reinforcement. Reinforcement could be cookies, could be attention from me (pats, praise, etc), it could be toys and interactive play or it could be freedom to go and make other choices.
A typical young puppy or early learner scenario:
I like using food for this exercise because it lends for high rate of reps in a short amount of time - you can use toys of course, but keeping sessions short you will have significantly fewer reinforcement opportunities. There's potential of course that the play reps are higher value to puppy though too.
Once you reach PEZ dispenser status in no distraction/low stimulus environments it's time to take the show on the road! Head off to a couple of places (or move to the other side of your driveway) and work the same attention behaviors. Remember to keep these sessions short and successful. If you get stuck with a puppy who really isn't focused on anything other than grass, bird poop, sticks, etc - back up with your goals. Get a couple of super-successes and end the session on that positive note.
The same basic game is used for shaping behaviors - offer, think, stay engaged, keep trying 'stuff' and you're going to get something. The most successful operant dogs are the ones who have figured out that try = good and mistakes = no big deal/try something else.
The Definition of operant from Miriam-Webster:1 : functioning or tending to produce effects : effective