Response to intervention (commonly abbreviated RtI) is a method of academic intervention used in the United States to provide early, systematic assistance to students who are having difficulty learning. RtI seeks to prevent academic failure through early intervention, frequent progress measurement, and increasingly intensive research-based instructional interventions for students who continue to have difficulty. It is believed that students who do not show a response to effective interventions are likely (or, more likely than students who respond) to have biologically based learning disabilities and to be in need of special education.
In terms of identifying learning disabilities, the RTI method was developed as an alternative to the ability–achievement "discrepancy model," which requires students to exhibit a discrepancy between their ability (often measured by IQ testing) and academic achievement (as measured by their grades and standardized testing). Proponents of RTI contend that the process brings more clarity to the Specific Learning Disability (SLD) category of the Individuals with Disabilities Education Improvement Act (IDEA 2004).
RTI is a general education framework that involves research-based instruction and interventions, regular monitoring of student progress, and the subsequent use of these data over time to make educational decisions. Key to the RTI process is the application of scientifically based interventions that have been demonstrated to work in randomized controlled trials. A goal of the RTI process is to apply accountability to educational program by focusing on programs that work rather than programs that simply look, sound, or feel good.
RTI follows a number of core assumptions:
The educational system can effectively teach all students
Early intervention is critical to preventing problems from getting out of control
The implementation of a multi-tiered service delivery model is necessary
A problem solving model should be used to make decisions between tiers
Research based interventions should be implemented to the extent possible
Progress monitoring must be implemented to inform instruction
Data should drive decision making
In the RTI process, service delivery is divided into three levels (tiers) of support, with the intensity of interventions increasing with each level. Tier 1 is focused specifically within the core curriculum, with instruction and interventions targeting all students. Approximately 80% to 85% of the general student body should be able to meet grade level norms without additional assistance beyond the first tier. Students who consistently do not perform within the expected level of performance through Tier 1 instruction are then provided with additional supplementary interventions at Tier 2, which typically involves small group instruction. Approximately 3% to 6% of students will continue to have difficulties after Tier 2 interventions; these students will then receive Tier 3 intervention services, which is the most intense level of intervention (often one-on-one) provided in the regular education environment. As RTI is a regular education initiative, all three tiers of services are intended to be provided as supplements to, not replacements for, the regular education curriculum.