Fidelity of implementation is related to student success in an intervention. Reaching PBIS fidelity indicates that the school is implementing the core components as indicated by the research of effectiveness. Schools in Illinois achieving fidelity of PBIS implementation are seeing benefits to students in the form of reduced out of school suspensions (OSSs) and discipline referrals.

Reducing Suspensions for Elementary Students with IEPs

A group of Illinois elementary schools implementing PBIS (N=191 schools) at fidelity in both FY12 and FY13 experienced a

reduction in out of school suspensions (OSSs) for all students, including those with Individualized Education Programs (IEPs). 

Between FY11 and FY13, the OSS rate for students with IEPs decreased 42%, from 0.069 in FY11 to 0.040 in FY13. Likewise, 

the rate for students without IEPs decreased 41%, from 0.091 in FY11 to 0.054 in FY13.

During this time, the risk ratio for OSSs for students with IEPs went down 20%. Students with IEPs were less likely to 

receive OSSs over the three years and were, in fact, less likely to receive an OSS compared to their peers without IEPs.

 Middle School Success: Reducing Office Discipline Referrals for Students with IEPs

From FY11 to FY13, 37 Illinois PBIS middle schools monitored both discipline data by IEP status and fidelity of implementation

for Tier 1 PBIS. Over the three years, students with IEPs in these schools experienced a 12.5% decrease in ODR rate, 

from 1.011 in FY11 to 0.885 in FY13.