Final answer:
David's potty chart is an example of using positive reinforcement in behavior modification.
Step-by-step explanation:
David's potty chart is an example of positive reinforcement, which is a technique used in behavior modification. Positive reinforcement involves giving a reward or incentive to encourage a desired behavior.
In this case, each time David uses the potty, he gets a sticker on his chart. Once he reaches ten stickers, he receives a new Hot Wheels car as a reward.