If your son ditches the aide, then CONSEQUENCES!
-Ramp up the monitoring. If you can go to school and observe your son too, then do so each time he ditches the aide. (A parent sitting in on school classes can work WONDERS for behavior problems! Arrange it ahead of time with the school/teacher. Then just walk in after class has started and sit quietly in the back. Leave before class ends. Don't say a word to anyone - don't wave to your son. Etc. Just be a fly on the wall!)
-Kid goes to school's "time out room" for lunch instead of being allowed outside if he can't stay in view of the aide.
-Etc. Might want to attend a parenting class (ask school counselor if they have them in your area). Other parents at these classes can think of all sorts of things to do [which have worked in the past] for their kids.
-And on the positive side, do special things for your son if he can go a period of time [a week?] without ditching the aide. (You get a good report from the aide.)
