My five year-old son has been having behavior issues at school. To encourage him to improve, I promised to take him out to a movie whenever he had a full week of "greens" on the behavior chart his teacher sends home. At the time, he was getting 3 or 4 greens a week. Now, a couple months later, he is averaging only around one per week.
Obviously, the technique isn't working. It motivates him at home in the evenings. He often says excitedly, "I'm going to be good at school tomorrow so I can see the movie!" However, at school it isn't making any difference. I'm not sure it's within his capabilities at the moment. I thought it would result in postponing movies for two or three weeks, not in never being able to see a movie with him at all, so I want to back out of the deal.
I'm not sure how to go about it without undermining my credibility, though. I don't want him to think he can just hold out until the standards are lowered. I believe this is an exceptional circumstance, and intend to be more careful about setting standards in the future. Any thoughts?
Edit: Judging from some answers, I suppose I should mention that we also do daily consequences depending on what he did. For example, extra homework from the lesson he wasn't paying attention to. We also praise him daily when he does a good job. I consider that a separate issue from the five in a row requirement, which was intended to address his inconsistency.