One example of a tiered system is the three-tiered model described by McCook (2006):
Tier I- General Education core instruction
Tier II- Strategic, targeted group instruction
Tier III- Intense individual or group instruction
Tier I should benefit about 80-90% of students and represents the general education curriculum. In Tier I, students receive differentiated instruction (giving students multiple and varied opportunities to learn new information) that meets the needs of a majority of the students. Students in Tier I receive universal screenings at the beginning of the year to see if they are having any difficulties and their progress is monitored in the middle and end of the year.
Students that struggle in Tier I (about 5-10%) may need to be moved to Tier II to receive targeted assistance. Typically, students are taught in smaller groups for a specific period of time, and educators monitor their progress more frequently to see if they are responding to the intervention. The small number of students that do not respond to Tier II interventions will move to Tier III.
In Tier III, the intervention is for a specific period of time and is more intense than Tiers I and II. Teachers or Special Educators may provide these interventions in small groups or individually. Progress monitoring is critical to determining a student’s response to intervention. If a student does not respond at this level, then he/she may receive a referral for special education services (Moore & Montgomery, 2008).