The Tier 1.5 Calculator is a tool designed to help educators identify classrooms that are not responsive to Tier 1 instruction and could benefit from a classwide intervention, also known as Tier 1.5.  

What Is Tier 1.5?

Researchers recommend schools adopt Multi-Tiered System of Support (MTSS) to prevent reading difficulties and support the reading development of PK–12 students (Burns et al., 2016). A critical part of MTSS is the delivery of high-quality, evidence-based literacy instruction to all students—known as Tier 1 or core instruction. Although core instruction is intended to benefit all students, some students may require additional support.

Specifically, when a significant portion of students in a classroom are identified as needing Tier 2 or Tier 3 interventions, educators are encouraged to focus on strengthening Tier 1 instruction (Burns et al., 2014). One way to do this is through a Tier 1.5 intervention. For example, this may involve providing intensified instruction and practice opportunities for skills that the majority of students in the classroom are struggling with, such as fluency or vocabulary. 

How Do I Determine Whether Tier 1.5 Is Needed?

Broadly speaking, a classwide intervention is needed when most students are having difficulty. You may consider using a formal rule or criteria to help determine when this is the case. Prior studies have determined the need for intervention by comparing class median scores on a screening assessment (e.g., 2021 FastBridge, DIBELS 8, 2020/Version 3 easyCBM) to a set criterion—a specific percentile rank (e.g., 25^th percentile or 40^th percentile). If the class median falls at or below the selected criterion, then Tier 1.5 is recommended.    

Using the Tier 1.5 Calculator, educators can upload their classroom’s scores for FastBridge, easyCBM, or DIBELS to see where your class median score falls relative to these important cutoff points. 

Check out the following blog posts to learn how to make the most of the Tier 1.5 Calculator.