The basis for using stickers and a chart is really simple- to provide a visual reward for positive behavior. Children love to have their work displayed, and potty training charts capitalize on that fact. The positive incentive encourages the desired behavior. The child practices the behavior enough that it becomes habit, and before you know it, the child is potty trained. Charts and stickers provide a visual reinforcement, a reminder of the progress
being made, and are motivating for both parents and children.
There are several ways to approach potty training with rewards. The key is to have your child feel a sense of pride and accomplishment for her hard work. Keep in mind you don't want her to feel bribed, or left feeling disappointed if she is unable to earn a reward.
You know your child best, so try to design a "reward system" that you think will work for your child. The "reward system" could be as simple as a sticker for each time your child goes to the potty. Or you might decide to reward your child each time she attempts to go to the potty. You choose the "rewardable behavior".
An increment of time or a certain number of "rewardable behaviors" lead to a "milestone reward". For instance, after 10 stickers or a day of trying, you could recognize your child's effort by reading her an extra story or singing an extra song at bedtime. To keep your toddler motivated, you can increase the value of the "milestone reward" as she progresses.
For example: at the end of the week, your child may get to select a toy from a "treasure chest" (a bin you have filled with new toys) or you may make a trip to the movies or you take her for a visit to her favorite park.
A caveat in regards to rewards:
If the reward is too big, then you child will be more focused on trying to get the reward and may get frustrated when she is unable to collect the reward as fast as she'd like.
Be flexible, making adjustments when needed.
For example: one mom used M & M's for urinating in the potty. This worked well in the beginning, but then her daughter figured out that she could urinate just a bit and still get an M & M. Next thing she knew, instead of urinating all at one time, her daughter would urinate a bit at a time to get those M & M's. She had to change the rules on her daughter. She drew a line inside the potty and told her daughter that she would now get an M & M only after the urine reached that line.
Remember, the best rewards for children are as simple as extra attention from a parent. Verbal praise, extra hugs & kisses and extra quality time with a parent may go a much longer way in comparison with material rewards.