3.2 Multi-Tiered System of Supports (MTSS) and Response to Intervention (RTI) Frameworks

3.2 Multi-Tiered System of Supports (MTSS) and Response to Intervention (RTI) Frameworks

SLLA Exam Focus: Questions regarding Multi-Tiered System of Supports (MTSS) and Response to Intervention (RTI) on the SLLA evaluate an administrator's capacity to lead preventative schoolwide systems. ETS scenarios can test the difference between core instruction and supplemental interventions, the use of progress-monitoring decision rules, and the legal intersection between RTI and the Individuals with Disabilities Education Act (IDEA). Tier percentages, group sizes, schedules, and decision rules are local implementation choices rather than fixed ETS or federal mandates. Most importantly, an RTI process cannot be used to delay or deny an IDEA evaluation when a disability is suspected; a district must respond promptly to a parent's request by proposing an evaluation and seeking consent or by issuing prior written notice explaining a refusal.

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The Multi-Tiered System of Supports (MTSS) Architecture

Multi-Tiered System of Supports (MTSS) is an overarching, schoolwide prevention framework that systematically identifies and supports students who have academic, behavioral, attendance, or social-emotional needs. MTSS integrates what were historically separate initiatives—Response to Intervention (RTI) for academics and Positive Behavioral Interventions and Supports (PBIS) for behavior—into a single, unified problem-solving infrastructure.

The MTSS framework is organized into three distinct tiers of increasingly intensive, evidence-based instructional support:

Tier 1: Universal Core Instruction (commonly planned so about 80%–85% succeed)

• Focus: High-quality, standards-aligned core curriculum delivered to all students in the general education classroom.
• Pedagogy: Teachers employ Universal Design for Learning (UDL), culturally responsive pedagogy, evidence-based instructional strategies, and routine in-class differentiation.
• Benchmark Target: In a healthy, functioning school system, a common planning benchmark is for Tier 1 core instruction to meet the academic and behavioral needs of approximately 80% to 85% of the student population without supplemental interventions.
• Administrative Role: If universal screening reveals that 35% or 40% of students in a grade level are falling below benchmark, the principal should investigate Tier 1 curriculum, instruction, screening validity, and implementation before assuming that every flagged student has an individual deficit. Resources must be directed toward curriculum alignment, professional development, and core instructional fidelity before flooding Tier 2.

Tier 2: Targeted Supplemental Interventions (often about 10%–15% of Students)

• Focus: Targeted, small-group instruction designed to remediate specific foundational skill deficits identified through universal screening.
• Delivery Model: Often uses a validated standard treatment protocol delivered to a small group with shared skill deficits (for example, phonemic segmentation, reading fluency, or fraction operations).
• Dosage & Schedule: Frequency, duration, group size, and provider qualifications must follow the selected intervention's evidence base and local plan; the examples in the comparison table are planning illustrations, not legal minima.
• Critical Mandate — Supplemental, Not Supplanting: Tier 2 intervention must be in addition to, never in place of, Tier 1 core instruction. Pulling struggling students out of their Tier 1 grade-level reading or math block to receive Tier 2 remediation creates a "double deficit" where students fall further behind on grade-level standards.

Tier 3: Intensive Individualized Interventions (often about 1%–5% of Students)

• Focus: Highly intensive, customized instruction targeted at severe, persistent academic or behavioral deficits that have not responded adequately to high-fidelity Tier 2 interventions.
• Delivery Model: Uses a problem-solving protocol to develop an individualized intervention plan tailored to the student's diagnostic profile, often in a very small group or one-to-one setting.
• Dosage & Schedule: Delivery is more intensive than Tier 2, with frequency and duration selected from student data and the intervention's design rather than a universal federal schedule.
• General Education Context: Tier 3 remains a general education support within the MTSS framework. While students with persistent lack of response in Tier 3 may be referred for special education evaluation, Tier 3 itself is not synonymous with special education.

MTSS Tier Comparison Matrix (Illustrative Local Design)

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Universal Screening and Curriculum-Based Measurement (CBM)

A foundational tenet of MTSS is early identification and prevention. Rather than adopting a passive "wait-to-fail" approach, schools deploy systematic assessment tools to catch struggling learners before achievement gaps widen.

Universal Screening Protocol

Universal screening uses brief, reliable assessments with all students on a schedule set by the school or district. Fall, winter, and spring screening is a common design, but the frequency is not a universal IDEA or ETS requirement.

Screeners establish cut-scores that classify students into risk tiers (e.g., Low Risk / Tier 1, Moderate Risk / Tier 2, High Risk / Tier 3). Prominent universal screening systems include DIBELS (Dynamic Indicators of Basic Early Literacy Skills), Acadience, AIMSweb, and FastBridge.

Curriculum-Based Measurement (CBM)

Curriculum-Based Measurement (CBM) is a widely used tool for screening and progress monitoring in an RTI framework. CBM instruments possess distinct psychometric characteristics:

• Brief & Timed: Typically 1 to 3 minutes in length (e.g., Oral Reading Fluency [ORF], Nonsense Word Fluency [NWF], Math Computation Probes).
• Direct Measures of Foundational Skills: CBM directly samples the critical basic skills underlying academic proficiency rather than assessing abstract constructs.
• Standardized Administration & Objective Scoring: Strict administration rules and explicit scoring rubrics ensure high inter-rater reliability.
• Multiple Parallel Forms: CBM systems contain dozens of alternate, equivalent forms of identical difficulty, allowing educators to test students repeatedly over weeks without test-practice distortion.
• Sensitivity to Short-Term Growth: Unlike broad standardized tests, CBM probes are sensitive to small, incremental gains achieved over a 4- to 8-week intervention window.

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Progress Monitoring: Baselines, Aimlines, and Decision Rules

Collecting progress monitoring data is pointless unless the school adheres to clear, empirical decision rules that dictate when an intervention must be maintained, modified, intensified, or faded.

Constructing the Progress Monitoring Graph

1. Establish the Baseline: Before launching an intervention, administer three separate parallel CBM probes over several days. The median score of these three probes establishes the student's true baseline performance level.
2. Establish the Goal & Aimline: Determine the target benchmark score for the end of the intervention period (typically 8 to 12 weeks). Draw a straight line on the graph connecting the baseline median to the target goal. This line represents the aimline (the expected rate of improvement or target slope).
3. Plot Data Points: Administer a single parallel CBM probe at regular intervals (bi-weekly for Tier 2; weekly for Tier 3) and plot the score on the graph.

One Common Four-Point Decision Rule

Instructional leaders train Student Support Teams (SSTs) to use a district-adopted, research-supported decision rule consistently. One common graphing rule is:

• Rule 1: Intensify / Alter Instruction: If four consecutive data points fall below the aimline, the student is not making adequate progress. The team must convene to modify or intensify the intervention (e.g., increase instructional time, reduce group size, change the pedagogical approach, or diagnose unaddressed prerequisite gaps).
• Rule 2: Fade / Exit Intervention: If four consecutive data points fall above the aimline, the student has accelerated beyond the target rate of improvement. The team should consider gradually fading the intervention and returning the student to Tier 1 core instruction with ongoing universal screening monitoring.
• Rule 3: Maintain Intervention: If the data points oscillate around the aimline, the student is progressing at the expected rate. The team maintains the current intervention protocol until the scheduled review date.

Auditing Fidelity of Implementation

Before an instructional team concludes that a student has "failed to respond" to an intervention, the school leader must verify implementation fidelity. An intervention cannot be evaluated if it was not actually delivered as intended. Leaders audit four dimensions of fidelity:

1. Adherence: Was the evidence-based program delivered exactly according to its validated design and instructional sequence?
2. Dosage: Did the student receive the prescribed minutes per day and days per week? (Reviewing attendance logs to ensure sessions were not canceled due to assemblies, testing, or staff absences).
3. Quality of Delivery: Did the interventionist employ effective explicit modeling, corrective feedback, and student engagement strategies?
4. Student Responsiveness: Was the student actively engaged during the sessions?

Exam Trap: When a team is judging whether an intervention worked, it should check fidelity logs before attributing weak progress to the student. That review must never delay child-find duties, a prompt response to a parent request, or an evaluation when disability is suspected.

The Dual Discrepancy Model & IDEA Special Education Identification

Prior to the reauthorization of the Individuals with Disabilities Education Act (IDEA 2004), school districts relied on the "severe discrepancy model" (the IQ-achievement discrepancy) to identify Specific Learning Disabilities (SLD). This outdated model required a student's academic achievement to fall significantly below their cognitive ability (IQ) before qualifying for services—a practice widely condemned as a "wait-to-fail" model.

IDEA 2004 authorized schools to use a scientific, research-based Response to Intervention (RTI) process as an alternative identification model. Central to this approach is the Dual Discrepancy Model.

The Dual Discrepancy Framework

Under one RTI identification approach, a dual discrepancy can be important evidence, but it does not by itself establish IDEA eligibility. The multidisciplinary team must apply the state's SLD criteria, use multiple data sources, and consider exclusionary factors:

1. Performance Level Discrepancy: The student's current academic performance level is substantially lower than that of their grade-level peers and established benchmark standards.
2. Rate of Growth Discrepancy: The student's rate of learning (slope of improvement on progress monitoring graphs) is substantially slower than that of peers, even when provided with high-quality, scientifically validated Tier 2 and Tier 3 interventions delivered with documented fidelity.

If a student performs below grade level but makes rapid growth with high-quality intervention, the data may not show a dual-discrepancy pattern. The team must still consider all evaluation data rather than declaring the cause from intervention response alone.

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Parent Involvement, Due Process, & SLLA Exam Traps

Navigating the legal boundary between MTSS and Special Education is among the most heavily tested legal concepts on the SLLA. School leaders must balance early intervention with strict adherence to federal special education procedural safeguards.

The Right to Request Evaluation and Receive a Prompt Response

Under IDEA and federal regulations (34 C.F.R. § 300.301), a parent may request an initial evaluation at any time. A request does not guarantee that the district must evaluate in every case, but the district must respond within a reasonable period: propose an evaluation and seek informed consent, or refuse and provide prior written notice explaining the evidence and reasons.

• No Required MTSS Completion: A school district CANNOT delay, postpone, or deny a parent's written request for a special education evaluation on the grounds that the student has not completed all tiers of MTSS/RTI.
• The SLLA Golden Rule: When a parent submits a written evaluation request, the school must either: (1) initiate the formal evaluation process by providing the parent with a Prior Written Notice (PWN) and an evaluation consent form within state-mandated timelines (typically 10 to 15 school days), or (2) provide the parent with formal Prior Written Notice explaining the legal and educational justification for refusing the evaluation, along with the applicable procedural-safeguards notice.
• Parallel Implementation: If the parent consents, IDEA's 60-day evaluation timeline (or the state's timeline) begins; the school should continue appropriate Tier 2 or Tier 3 supports while the evaluation proceeds. RTI and formal evaluations occur concurrently, not sequentially.

Parent Notification in RTI

Schools should communicate clearly with families when a student enters targeted or intensive intervention, and state law or district policy may require written notice. When an RTI process is used as part of SLD evaluation procedures, IDEA also requires the applicable procedural notice. Useful intervention communication includes:

• The specific academic or behavioral deficit identified
• The nature, frequency, and duration of the intervention program being provided
• The progress monitoring tools being used and regular reporting intervals
• The parent's continuous legal right to request a formal special education evaluation under IDEA

Critical SLLA Exam Traps in MTSS/RTI