Age group(s) for which this technique is helpful:
Preschool and Younger
Elementary School
Middle School
High School & Beyond

Primarily used to improve behavior:
Both At Home and At School

Instructions for using this technique:
The Mystery Surprise Calendar can work for any child of any age. You will need an invisible marker, the decoder marker, (available at paper stores) and a calendar. On the calendar you mark 3 days the first month with a mystery surprise. My family used items like staying up a half hour later to read, rent a movie, play a game with mom and dad.
You will need to find what will motivate your child. The university professor who used this to motivate his students used pulling the hair off of his legs with masking tape.

You can be as creative as your child and family will let you. Then isolate a desired behavior. (Example: complete and hand in all homework.) Each day the child performs the desired behavior they earn a chance to use the secret decoder pen for that day.

Remember, not every day has a surprise under it. The suspense is the reward. After the first month - drop the surprise to two days per week, the third month - one day per week and so forth.

After the third month, isolate a new behavior and start over again.

Other information parents should consider before using this technique:
Tip: This can be used for adults to change a behavior as well. Remember to include the whole family if at all possible.

Please try and remain positive. This does work.