Effectiveness of PBIS

While difficult to measure objectively and statistically due to the lifelong time element and multidimensional aspects of PBIS, there is some evidence available from schools related to its effectiveness.
Olson Park Elementary School in Loves Park reports a 40% decrease in its Office Behavior Reports from September, 2001 to September, 2002 due to implementing PBIS (FY03 PBIS 1st Quarter 2002).

Kentucky Schools indicate a 66% decline in office referrals due to implementation of a PBIS program, and a 64% decrease in school suspensions and expulsions. During the 1997-98 school year, one Kentucky school did not have a PBIS program in place. After implementing it the following year, the school showed a 65% decrease in the number of students suspended, a 76% decrease in the number of days of suspension school-wide. They also experienced an increase in reading scores attributed to a greater number of instructional hours (Positive Behavior Support and Delinquency Prevention, 2004)

The state of Maryland is a national model for effective use of PBIS. With state mandates to utilize the program, and routine training of teachers and school administrators by the state board of education, Maryland schools benefit from a proven track record of decreased numbers of school suspensions, and less class time lost to handle behavior situations. Nancy S. Grasmick, State Superintendent of Schools claims, "PBIS is so successful because it focuses on changing behavioral expectations within schools, not just individual student behaviors. As a result, school cultures and environments have changed, making way for the kind of academic learning that we want for all Maryland’s children." (MSDE to Train Educators. . . 2004)
(http://wik.ed.uiuc.edu/index.php/PBIS_(Positive_Behavioral_Interventions_and_Supports)