The Advanced Tiers represent increasingly intensive instructional and/or behavioral supports for learners who have not yet made grade-level expectations, with distinctions between Tiers 2 and 3. Tier 2 intervention intensity is defined as interventionists delivering intervention using evidence-based curriculum resources and/or strategies with more frequent progress monitoring. These progress-monitoring data are used, along with fidelity data, to determine if learners are responding to the intervention as expected. If learners are not responding to the intervention instruction as expected, and such factors as student attendance and intervention fidelity have been ruled out as possible causes, the Multidisciplinary Team (MDT) plans for Tier 3 intervention support. Intensification can happen at the group or individual student level.
Tier 3 is the most intensive level of intervention for general and special education students. It is more individualized, meaning progress-monitoring data are further analyzed to identify the possible reason(s) why the Tier 2 intervention instruction was not effective. Additional diagnostic data may be collected to help determine the right next step(s) to intensify the intervention instruction. Tier 3 intervention supports continue to utilize evidence-based curriculum resources. Usually, these are the same curriculum resources used during Tier 2 instruction, but with key distinctions. The main distinction is the individualization of the instruction. The Multidisciplinary Team works with the learner, their family/caregivers, and other adults in their lives to create an individualized intensive intervention plan. This plan outlines how the intervention instruction will be adapted to increase dimensions such as behavioral supports, comprehensiveness (explicitness) of the intervention instruction, and helping learners transfer (generalize) what they are learning during the intervention lessons to other contexts or settings. An individualized progress-monitoring plan ensures alignment between the intervention instruction and the progress-monitoring measures. Fidelity in Tier 3 is focused on adhering to the components outlined in the individualized intensive intervention plan. Data are analyzed to determine how the learner responds to the intervention instruction, and when needed, the plan is adjusted to further intensify the support (St. Martin, Harms, Walsh, & Nantais, 2023).