3.- Describe multi-tiered systems of instruction (MTSS), response to intervention (RTI) and pre- referral interventions. What are the major purposes of these systems? Describe concerns regarding MTSS, RTI, and evaluation. The IDEA 2004 does encourage schools to use an evaluation process that determines if a student responds to scientific, research-based interventions. How can such a model be implemented successfully in schools? What are the implications for special education