From the National Center for Learning Disabilities, always reliable:
http://www.ncld.org/parents-child-disabilities/ld-testing/strategies-addressing-identification-issues?utm_source=LDOnLine.org&utm_medium=Twitter
If the school informs you that they are using Response to Intervention (RTI), you should go ahead and request an evaluation in writing as soon as you think your child may have a disability. Making this request is critical because your written consent puts a 60-day timeframe on both the completion of the RTI process and the evaluation. The process of determining whether your child has a disability such as a learning disability and needs special education cannot go on indefinitely. If your request for an evaluation is denied because your child’s school says they do not “suspect” a disability or because they are using RTI, you have the right to file either a due process complaint or a state complaint, discussed later.
