Multi-Tier System of Supports (MTSS)/ Response to Intervention (RtI)

In this chapter the focus will be on response to intervention (or instruction) RTI, which now falls under the umbrella of the more encompassing Multi-tiered System of Supports MTSS.In addition to the RTI academic focus, MTSS includes a focus on the behaviorial needs of students under the title of Positive Behaviorial Supports and Interventions (PBIS)

WikiDaily, (2020). Response to Intervention, Content is available under CC BY-SA 3.0

In education, response to intervention[1] (commonly abbreviated RTI or RtI) is an approach to academic intervention used in the United States to provide early, systematic, and appropriately intensive assistance to children who are at risk for or already underperforming as compared to appropriate grade- or age-level standards. RTI seeks to promote academic success through universal screening, early intervention, frequent progress monitoring, and increasingly intensive research-based instruction or interventions for children who continue to have difficulty. RTI is a multilevel approach for aiding students that is adjusted and modified as needed if they are failing.

In terms of identifying students with specific learning disabilities (SLD),[2] RTI was proposed as an alternative to the ability–achievement discrepancy model, which requires children to exhibit a significant discrepancy between their ability (often measured by IQ testing) and academic achievement (as measured by their grades and standardized testing). Methods to identify students with SLD have been controversial for decades[3] and proponents of RTI claim that the process brings more clarity to the Specific Learning Disability (SLD) category of the Individuals with Disabilities Education Improvement Act (IDEA 2004),[4] while opponents claim that RTI simply identifies low achieving students rather than students with learning disabilities.

RTI is originally a special education term that has broadened into 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 a variety of educational decisions, including, but not limited to SLD eligibility.[5][6][7] To facilitate this broadened conception of RTI, there was a shift to labeling this as one of the approaches of a Multi-Tier System of Supports (MTSS) occurring in schools and the professional literature.[8] The key to the RTI process is the application of scientifically based interventions that have been demonstrated to work in randomized controlled trials.[9] A goal of the RTI process is to apply accountability to the 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:[5]

  1. The educational system can effectively teach all children
  2. Early intervention is critical to preventing problems from getting out of control
  3. The implementation of a multi-tiered service delivery model is necessary
  4. A problem solving model should be used to make decisions between tiers
  5. Research based interventions should be implemented to the extent possible
  6. Progress monitoring must be implemented to inform instruction
  7. Data should drive decision making

School-wide screening

The first level of data collected in the Multi tired system of support/ RTI process, comes from universal school-wide screenings. These screening assessments are typically given to all students within targeted grade levels, and cover basic academic subjects such as reading and mathematics. Most screening measures aim to be practical and efficient to administer, with the goal of identifying students who may require further assessments and interventions.

To evaluate student performance on the screening measures, scores are compared to specific criteria (criterion referenced) or to broad norms (norm referenced). When specific criteria are used, cut scores are established to evaluate students against a specific level of proficiency (e.g., achieving a score of 15 or above); in a normative comparison, students’ scores are compared against those of a larger group (e.g., scoring above the 25th percentile compared to a national sample of 3rd grade students).

Screenings usually occur three times per year (fall, winter, and spring), and the data from these assessments help to guide instruction through the three tiers of the RTI process. This is important not only for identifying students who are having difficulties, but also for identifying possible areas of improvement in the general classroom instruction in the cases where too many students fall below expectations.[15] Because a single universal screening at the beginning of the year can over-identify students who require preventive intervention, the National Research Center on Learning Disabilities recommends that schools also integrate at least five weeks of weekly progress monitoring to identify students who require preventive intervention.[16]


Core curriculum in the classroom should be research-based and field tested. This means, based on evidence from congregating research, that the core curriculum contains all the fundamentals found necessary to efficiently teach reading and has a recognized record of achievement. Such curriculum is to be delivered by “highly qualified” teachers adequately trained to deliver the selected instruction as intended, that is, with fidelity to design.

Progress monitoring and a multi tiered service delivery

Progress monitoring is a set of assessment procedures for determining the extent to which students are benefiting from classroom instruction and for monitoring effectiveness of curriculum.

Curriculum-based measurement (CBM)[17] is often used to collect data on interventions and their effectiveness to determine what works best for an individual student. Additional methods are attempted until students “respond” to the intervention and improve their skills. Students that do not respond, or respond at significantly low rates, may be deemed to have learning disabilities, rather than simply learning difficulties.

Progress monitoring is the scientifically based practice of assessing students’ academic performance on a regular basis for three purposes:

  1. To determine whether children are profiting appropriately from the instructional program, including the curriculum
  2. To build more effective programs for the children who do not benefit
  3. To estimate rates of student improvement

Three tiers of Scientifically Research-Based Interventions (SRBIs) of increasing intensity incorporate the key components of Multi tiered system of support/ RTI and help ensure the academic growth and achievement of students.

Tier 1

The first tier states that all students receive core classroom instruction that is differentiated and utilizes strategies and materials that are scientifically research-based. Assessment in the classroom should be ongoing and effective in that it clearly identifies the strengths and weaknesses for each learner. Any necessary interventions at this level are within the framework of the general education classroom and can be in the form of differentiated instruction, small group review, or one-on-one remediation of a concept.

Progress monitoring in Tier 1 uses universal screening assessments to show individual student growth over time and to determine whether students are progressing as expected. In this process, data are collected, students are identified using benchmark scores, and measurable goals are set for the next data collection point for those who display difficulties. The team then follows a problem-solving process to determine interventions for at-risk students that will work within whole-class instructions. The classroom teacher implements the interventions, observations are conducted to ensure the fidelity of the classroom instruction, and the problem-solving team periodically reviews the progress of students.

[The Swift Center]. (2017, Jul. 27). MTSS: Universal Support [Video File]. Retrieved from

Tier 2

In the second tier, supplemental interventions may occur within or outside of the general education classroom, and progress monitoring occurs at more frequent intervals. Core instruction is still delivered by the classroom teacher, but small groups of similar instructional levels may work together under a teacher’s instruction and/or guidance. This type of targeted instruction is typically for 30 minutes per day, two to four days per week, for a minimum of nine weeks. This targeted instruction may occur in the general education setting or outside in a smaller group setting with a specialized teacher (such as a Literacy Support teacher for struggling readers).

In Tier 2, the main purpose of progress monitoring is to determine whether interventions are successful in helping students learn at an appropriate rate. Decision rules are created to determine when a student might no longer require extra interventions, when the interventions need to be changed, or when a student might be identified for special education.

[The Swift Center]. (2017, Jul. 27). MTSS:Additional Support [Video File]. Retrieved from

Tier 3

Tier three is for students who require more intense, explicit and individualized instruction and have not shown sufficient response to Tier 1 and Tier 2 interventions. This type of targeted instruction is delivered for a minimum of two 30-minute sessions every week for nine to twelve weeks. The interventions in this tier may be similar to those in Tier 2 except that they are intensified in focus, frequency, and duration. The instruction in Tier 3 is typically delivered outside of the general education classroom. Programs, strategies, and procedures are designed and employed to supplement, enhance, and support Tier 1 and Tier 2 instruction by remediation of the relevant area and development of compensatory strategies. If Tier 3 is not successful, a child is considered for the first time as potentially having a learning disability.

In some cases, Tier 3 is considered to be special education, with instruction being provided to individual students or small groups by special education teachers in place of general education instruction (rather than as a supplement). Initial goals are established through an individualized education program (IEP), which is guided by the results of a comprehensive evaluation, and ongoing progress monitoring helps to direct the teaching process. Special education instruction likely will be considerably longer than the 10 to 12 weeks of supplemental instruction delivered in Tier 2 and beyond. The frequency of special education instruction depends upon student need, and the criteria to exit special education are specified and monitored so that placement can be flexible.

[The Swift Center], (2017, July 27). MTSS:Intensified Support. [Video File]. Retrieved from

Multi tiered system of support/RTI implementation

The number of schools implementing RTI continues to grow and 61% of schools surveyed in 2010 indicated that they had fully implemented or were in the process of implementing RTI.[21]  RTI is primarily implemented by grade-level teams or professional learning communities as part of a school-wide problem-solving plan. Previous research found that implementing RTI resulted in several positive outcomes such as reductions in students referred to and placed into special education, more students passing state accountability tests, and increased academic skills among students at-risk for reading failure.[22]

Fidelity of implementation

In an Multi tiered system of support/ RTI model, fidelity is important at both the school level (e.g., implementation of the process) and the teacher level (e.g., implementation of instruction). Although the concept of fidelity of implementation is supported by research and is generally viewed as common sense, there are practical challenges associated with achieving high levels of fidelity. Factors that can reduce fidelity when implementing instruction include:[23]

  • Complexity of the interventions and the time required to implement them
  • Inaccessibility of required materials and resources
  • Low perceptions/expectations of effectiveness (teachers may not fully commit to an intervention if they believe that it will not be effective, or if it is inconsistent with their teaching style)
  • Low numbers, expertise, and motivation of those who deliver the interventions

Factors that can increase fidelity when implementing a Multi tiered system of support/ RTI model include:[24]

  • Well-functioning professional learning communities
  • Using a universal screener that is brief, aligned with the curriculum, result in reliable data, and is validated for screening decisions
  • Using a data-management system that is easily accessible by classroom teachers
  • Implementing interventions that address the skill deficit of students
  • Identifying and addressing class-wide needs
  • Establishing well-defined decision rules
  • Clear leadership from the building principal
  • Ongoing training and professional development
  • Key stakeholders working together in a flexible manner to improve student learning
  • Use of standard-protocol interventions for tier 2
  • Not making entitlement (i.e., special education disability identification) decisions until the RTI system is in place and well established.

Relationship between IDEA and RTI

The 1997 Individuals with Disabilities Education Act (IDEA) was revised as the Individual Disabilities Education Improvement Act (IDEIA) and signed into law in 2004, and it became effective in July 2006.[34][35] According to the law, a specific learning disability is a disorder of one or more of the basic psychological processes that adversely affects academic achievement in one or more domains (e.g., reading, writing, math, language). There are three methods of SLD identification under IDEA, as defined in §300.8(c)(10) (OSERS Final Regulations-8/06):

  1. a discrepancy between “ability” and “achievement”
  2. failure to respond to scientific research-based intervention
  3. alternative research-based procedures for determining whether a child has a specific learning disability

(The “third method” is often considered a “processing strengths and weaknesses” model.)

The 2004 reauthorization of IDEA makes mention of RTI as a method of part of the process of identifying SLD:

  1. In diagnosing learning disabilities, schools are no longer required to use the discrepancy model. The act states that, “a local educational agency shall not be required to take into consideration whether a child has a severe discrepancy between achievement and intellectual ability[…]”
  2. Response to intervention is specifically mentioned in the regulations in conjunction with the identification of a specific learning disability. IDEA 2004 states, “a local educational agency may use a process that determines if the child responds to scientific, research-based intervention as a part of the evaluation procedures.”
  3. Early Intervening Services (EIS) are prominently mentioned in IDEA for the first time. These services are directed at interventions for students prior to referral in an attempt to avoid inappropriate classification, which proponents claim an RTI model does. IDEA now authorizes the use of up to 15% of IDEA allocated funds for EIS.[36]

RTI was included in the regulations due to considerable concerns raised by both the House and Senate Committees regarding proponents of RTI claims about the use of IQ tests to identify learning disabled students. There was also recognition in these committees of a growing body of scientific research supporting methods of pre-referral interventions that resolved learning difficulties short of classification. However, the final regulations also allow a third method of SLD identification, often considered a processing strengths and weaknesses model.

The IDEA Committee Conference Report (CCR)[37] discusses the use of scientifically based early intervention programs, describes a model response-to-intervention program, and recommends the development of the most effective implementation of responsiveness to intervention models. The report describes such a model as an essential service for reducing the need to label children as disabled.

Through the establishment of the RTI process in IDEIA, schools could shift from a model that required teachers to wait for students to fail, to a model of prevention, offering extra support to students during the learning process.[38]

Concerns and criticisms of RTI for SLD classificationa 

Criticisms of the RTI model first surfaced in 2004 when IDEA identified it as a viable method for use in SLD eligibility determination[44] Some feel that RTI is valuable for prevention, but see little empirical support for using RTI to determine learning disabilities, and have concerns that it could be used to delay or deny services to children with learning disabilities.[45]

Why is it important to ensure students with disabilities are part of multi-tier frameworks?

In this video, Maryl Randle, a doctoral candidate in Special Education at Michigan State University & NCII Coach for the Swartz Creek School District, addresses the importance of ensuring that students with disabilities have access to supports across the tiers of a tiered framework, especially intensive intervention.
[National Center on Intensive Interventions] (2014, Oct. 2014).Why is it important to ensure students with disabilities are part of multi-tiered frameworks? [Video File]. Retrieved from

readings The IRIS Center. (2006). RTI (part 1): An overview. Retrieved from

Harlacher, J. E. , and Sanford, A.  (n.d.) Distinguishing Between Tier 2 and 3 Instruction in Order to Support Implementation of RTI. Retrieved from

*See Table 1: A Summary of Research-Based Factors that illustrate the Differences Between Tier 2 and Tier 3

References can be found at the bottom of the article at:

Image source

Reading- Image by Peggy und Marco Lachmann-Anke from Pixabay