Do you know if the teacher is consistently good about praising your son throughout the day when he is not having outbursts? I ask because, if she's not good about telling you about the good things, maybe she's not good about telling your DS about the good things either.
I think she does this, but I doubt she is able to remember to do it like we do at home. At home, we are two parents and one child. It's easy to notice times when we can praise, praise, praise. In a Montessori classroom, there is a lot of independent work time, so I don't know if she's in a position to praise like we'd suggest with the NHA.
That reminds me, btw, of a technique I heard from a teacher on tv the other night. She would draw a smiley face on the thumbs of her students when they'd have a good day so that they could go home, give mom or dad a thumbs up, and let their parents know they'd had a good day. What about suggesting a variation on this theme for your DS. Throughout the day when the teacher catches him controlling his responses to frustrating situations, she could draw a smiley face on one of his fingers (starting with his thumbs) and he could see how many smiley faces he could collect during the day. He wouldn't lose anything when he wasn't controlling himself, but he would gain something when he was. And it would just take half a second for the teacher to silently respond in a positive way.
I LOVE this idea! It is totally something that would work for ds. Immediate positive reinforcement works so well with him. I'm going to suggest it tomorrow, and I'm also going to look in to the ABA or CBT therapist.
Thanks so much!