**4. Overview of response to intervention**

Response to intervention's (RTI) foundation is rooted in prevention of science and evidencebased practice. This approach embraces special and general education through the use of three target areas: (a) effective curriculum that provides opportunity for the majority of students to progress at the expected rate, (b) universal screening for early identification at-risk students so that these students may be provided additional, focused, intensive instruction while their progress is monitored, and (c) intensive interventions to aid students with learning difficulty [3].

RTI emerged in the field of education based on research on specific learning disabilities (SLDs) and reading interventions. The results of SLD research influenced education laws and classroom practice [4]. In the United States of America, special education is governed by IDEA 2004. IDEA 2004 encouraged schools to use research-based interventions to differentiate between students struggling due to poor instruction or to a disability [5]. Prior to the reauthorization of IDEA 2004, a student may qualify for services under the SLD category by showing a discrepancy between achievement and aptitude on a qualified assessment. As a discrepancy model, SLD is the term used to describe a student performing at average or higher intelligence on a standardized test and performing at a significant discrepancy (usually two standard deviations) in one or more academic areas. Shortcomings of the discrepancy model led leaders in the field of SLD to propose RTI as a valid method of identifying a student with a learning disability [4]. Through the use of powerful, scientific-based procedures for decision making, RTI focuses on improving the outcomes in both general and special education [5].

RTI is more than a method of identifying students with learning disabilities; it is a way to ensure better academic outcomes for all students. RTI shifts the focus from individual intrinsic abilities and characteristics to environmental variables and instruction [6]. The shift also requires a closer look at individualizing instruction within the classroom and consistent monitoring of progress through validated, research-based techniques [5]. Further, RTI encourages educators to be proactive in identifying learning delays, ideally to prevent those delays from becoming learning disabilities. Educators can intervene as early as preschool and kindergarten. This model differs from the past practice of allowing the opportunity for students to fail in middle-elementary grades (e.g., second and third grades) before intervening with special education services [3].

RTI's proposed models involve two critical components: (a) evidence-based instruction and interventions implemented and (b) ongoing monitoring of student progress and responses throughout intervention. Valid instruction and interventions are defined as those leading to positive, reliable results for students with similar characteristics [5]. Thus, using RTI to identify students with SLD requires showing not only that a student demonstrates educational need but also an inconsistent response to high-quality general education instruction [7].
