E.
I have used this with my two kids (ages 6 and 8) for almost two years now and it works great. When they do something great; like clean their room or put away the dishes, they get a marble. However if they are fighting or not listening; they get one warning and then I take one away. we work this on a weekly basis. I think the short term helps them see the results. Then on Saturday they get a quarter for each marble in their jar. This way they can buy what they want or save for something bigger. My opinion.. Great system, rewards and punishment all on one.