Shaping is a type of operant conditioning that is used as a way to guide a subject’s behavior to have them do what you want them to do. In order to achieve this desired outcome, you must use successive approximations. Using these reinforcers to guide the actions means that you reward behavior that is nearing the desired outcome up to the point where that outcome occurs.
An example of shaping from my own life experiences occurred when I was training my dog to play fetch. First, I would train her to sit on the floor next to where I was standing by rewarding her with a treat. Next, I would train her to wait until I instructed her to run after the ball. After she successfully performed this step, I would again reward her with a treat. Once she was able to complete both of those previous steps consistently, I trained her to fetch the ball and return to me with it. Upon successful completion of these steps, she then received another treat. I then gave her an additional treat when she dropped the ball at my feet. Finally, I trained her that after giving me the ball, she should sit beside me again to wait for the next round of play. Once she performed this step, I would feed her another treat. Once she was used to regularly performing these steps, I would slowly start removing the treat rewards for each step. Eventually, she would play fetch following the steps outlined above without a reward.
In the example described above, rewarding my dog with treats was my way of using successive approximations to shape her to play fetch. During this training, the reinforcers I used were treats. I rewarded her with them whenever she completed an action that would lead to the overall behavior I wanted her to achieve: playing fetch. Rewarding her with those treats reinforced the behaviors that I deemed were important and useful to the overall goal.