I don't want to go in all raging b****, but I feel like I might have to!
Don't. Save it.
RTI is Response to Intervention. It is now required that schools intervene if they see an unusual need--they are supposed to apply resources and take care of it as soon as they see it, differentiating instruction earlier without requiring all kinds of hoops and testing. They are also supposed to be taking data to see if what they do is sufficient to make a change, and sufficient to solve the problem.
If it is, they keep doing it. If not, they go to the next stage, which is the full evaluation that leads to IEP or 504.
Now, if you think your DS needs direct services (speech, OT, etc) he will likely still need an IEP. But if not, you can keep going through the informal process to see whether it is sufficient.
This RTI process can mean that problems are solved faster and without IEP meetings and time-consuming formal plans, OR it can mean that solutions are delayed while they say they are trying stuff but doing so in a half-hearted manner. It puts more on the parents to act as watchdogs, IMO.
DeeDee
ETA: just saw your last message. It's great that they are going to do the full eval. A child with autism most likely needs an IEP.
