For anyone who's been hearing about Response to Intervention, but it still seems like an elusive new phrase being floated about in education-land, take the time to read Reid Lyon's explanation on Jay Greene's blog.
For those unfamiliar with the term "Response to Intervention," it is the attempt to reduce the number of students who are misidentified as needing Special Education services for reasons such as the student simply didn't receive reading instruction that allowed the student to actually learn to read. Not all children learn to read the same; add in the myriad of potential problems (i.e. visual tracking, auditory discrepancies) and often, the blanket approach just doesn't work. Instead, various tactics should be used before attaching the Special Education label.
However, Dr. Lyon addresses how complex and layered RtI is. It's hard to inculcate the philosophy into a school faculty, much less make sure the plan for assessment and intervention is broad enough to be effective for every student.